Re: python IDE and function definition

[Ben Finney]

Chris Friesen  writes:

> I'm running into issues where my current IDE (I'm playing with Komodo)
> can't seem to locate the definition, I suspect because it's too
> ambiguous.

The feature you're looking for – to start from the statement where a
function is called, then jump to the statement where that function is
defined – is implemented via “tags” across many languages and tools.

One very popular implementation is “Exuberant Ctags”. You can choose
from the tools http://ctags.sourceforge.net/tools.html> that
support that system, and continue using the same system when you switch
to a different language or a different tool.

> So rather than give up, I'd like to have my IDE suggest all possible
> answers.

Good luck to you in learning a development environment that is *not*
tied to the particular programming language you're writing.

-- 
 \  “… a Microsoft Certified System Engineer is to information |
  `\ technology as a McDonalds Certified Food Specialist is to the |
_o__)   culinary arts.” —Michael Bacarella |
Ben Finney

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Handling 3 operands in an expression without raising an exception

[Νίκος]

Hello,

How can i wrote the two following lines so for NOT to throw out 
KeyErrors when a key is missing?


city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or 
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or "Άγνωστη Πόλη"


host = socket.gethostbyaddr( os.environ['HTTP_CF_CONNECTING_IP'] )[0] or 
socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0] or "Άγνωστη Προέλευση"


I was under the impression that the 'or' operator was handling this in 
case one operand was failing but its not the case here.


I believe in a KeyError is missing the expression cannot even be 
evaluates as Truthy or Falsy.


Then i thought of os.environ.get() to default to something but then 
again we have 3 operand in the expression.

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Re: Handling 3 operands in an expression without raising an exception

[Jussi Piitulainen]

Νίκος writes:

> How can i wrote the two following lines so for NOT to throw out
> KeyErrors when a key is missing?
> 
> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
...
> I was under the impression that the 'or' operator was handling this
> in case one operand was failing but its not the case here.

"f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
if "f(x)" returns a false value and "g(x)" raises an exception.

> Then i thought of os.environ.get() to default to something but then
> again we have 3 operand in the expression.

Adapt this:

  >>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
  'catchall'

Or nest the calls this way if an empty string is a valid value:

  >>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
  ''

This will compute the default values even when they are not used.
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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 10:48 πμ, ο/η Jussi Piitulainen έγραψε:

Νίκος writes:


How can i wrote the two following lines so for NOT to throw out
KeyErrors when a key is missing?

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or

...

I was under the impression that the 'or' operator was handling this
in case one operand was failing but its not the case here.


"f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
if "f(x)" returns a false value and "g(x)" raises an exception.


Then i thought of os.environ.get() to default to something but then
again we have 3 operand in the expression.


Adapt this:

   >>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
   'catchall'

Or nest the calls this way if an empty string is a valid value:

   >>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
   ''

This will compute the default values even when they are not used.

I'am sorry but i do not understand the last statements at all so i can 
have chnace to adapt them.

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Re: Handling 3 operands in an expression without raising an exception

[Jussi Piitulainen]

Νίκος writes:

> Σ�ις 26/9/2013 10:48 πμ, ο/η Jussi Piitulainen
> έγ�α�ε: > ί�ος writes:
> >
> >> How can i wrote the two following lines so for NOT to throw out
> >> KeyErrors when a key is missing?
> >>
> >> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
> > ...
> >> I was under the impression that the 'or' operator was handling this
> >> in case one operand was failing but its not the case here.
> >
> > "f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
> > if "f(x)" returns a false value and "g(x)" raises an exception.
> >
> >> Then i thought of os.environ.get() to default to something but then
> >> again we have 3 operand in the expression.
> >
> > Adapt this:
> >
> >>>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
> >'catchall'
> >
> > Or nest the calls this way if an empty string is a valid value:
> >
> >>>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
> >''
> >
> > This will compute the default values even when they are not used.
>
> I'am sorry but i do not understand the last statements at all so i
> can have chnace to adapt them.

Do you know what {} is?

Do you know what {}.get('foo') is?

Do you know what x.get('foo') is if x is {}?

Do you know what {'empty':''}.get('empty') is?

Do you know what {'empty':''}.get('fruit') is?

Do you know what (None or '' or 'catchall') is?

Do you know what {}.get('foo', 'bar') is?

Do you know what {}.get('foo', {}.get('bar', 'huh')) is?

Do you know what ('foo'[3] or 'else') does?

Do you know what ('foo' or 'else'[5]) does?

Do you know how to launch an interactive Python session where you can
play with such expressions until you get the hang of it? There is no
substitute for that experience.

Do you know that you can ask for help({}.get) or help(dict.get) or
even help(os.environ.get) during such an interactive Python session,
and Python (unlike Macbeth's spirits from the vasty deep) will answer?
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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 11:12 πμ, ο/η Jussi Piitulainen έγραψε:

Νίκος writes:


Σ�ις 26/9/2013 10:48 πμ, ο/η Jussi Piitulainen
έγ�α�ε: > ί�ος writes:



How can i wrote the two following lines so for NOT to throw out
KeyErrors when a key is missing?

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or

...

I was under the impression that the 'or' operator was handling this
in case one operand was failing but its not the case here.


"f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
if "f(x)" returns a false value and "g(x)" raises an exception.


Then i thought of os.environ.get() to default to something but then
again we have 3 operand in the expression.


Adapt this:

>>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
'catchall'

Or nest the calls this way if an empty string is a valid value:

>>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
''

This will compute the default values even when they are not used.


I'am sorry but i do not understand the last statements at all so i
can have chnace to adapt them.


Do you know what {} is?

Do you know what {}.get('foo') is?

Do you know what x.get('foo') is if x is {}?

Do you know what {'empty':''}.get('empty') is?

Do you know what {'empty':''}.get('fruit') is?

Do you know what (None or '' or 'catchall') is?

Do you know what {}.get('foo', 'bar') is?

Do you know what {}.get('foo', {}.get('bar', 'huh')) is?

Do you know what ('foo'[3] or 'else') does?

Do you know what ('foo' or 'else'[5]) does?

Do you know how to launch an interactive Python session where you can
play with such expressions until you get the hang of it? There is no
substitute for that experience.

Do you know that you can ask for help({}.get) or help(dict.get) or
even help(os.environ.get) during such an interactive Python session,
and Python (unlike Macbeth's spirits from the vasty deep) will answer?


You dont have to be ironic. I dont have the experience you do.

Up until now i have this:

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or 
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or "Άγνωστη Πόλη"



can this be written as:

city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP', 
os.environ['REMOTE_ADDR'] )) or "Άγνωστη Πόλη"


It makes it more easily for me to understand this way.
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Re: Handling 3 operands in an expression without raising an exception

[Chris Angelico]

On Thu, Sep 26, 2013 at 6:12 PM, Jussi Piitulainen
 wrote:
> Do you know that you can ask for help({}.get) or help(dict.get) or
> even help(os.environ.get) during such an interactive Python session,
> and Python (unlike Macbeth's spirits from the vasty deep) will answer?

Speak, Python, speak!
We're all attention.
The news we seek
This moment mention!

ChrisA
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Re: Handling 3 operands in an expression without raising an exception

[Tim Golden]

On 26/09/2013 09:41, Chris Angelico wrote:
> On Thu, Sep 26, 2013 at 6:12 PM, Jussi Piitulainen
>  wrote:
>> Do you know that you can ask for help({}.get) or help(dict.get) or
>> even help(os.environ.get) during such an interactive Python session,
>> and Python (unlike Macbeth's spirits from the vasty deep) will answer?
> 
> Speak, Python, speak!
> We're all attention.
> The news we seek
> This moment mention!

I remember when I saw that in a production in Altrincham, the Prince
threw off his cloak dramatically to step forward-- and the clasp caught
on some part of his costume, reducing the effect somewhat as the cloak
dragged along behind. (In the end some other cast member came forward
and just ripped it free).

[G&S The Gondoliers, for those who weren't following along]

TJG
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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 11:46 πμ, ο/η Νίκος έγραψε:

Στις 26/9/2013 11:39 πμ, ο/η Νίκος έγραψε:

Στις 26/9/2013 11:12 πμ, ο/η Jussi Piitulainen έγραψε:

Νίκος writes:


Σ�ις 26/9/2013 10:48 πμ, ο/η Jussi Piitulainen
έγ�α�ε: > ί�ος writes:



How can i wrote the two following lines so for NOT to throw out
KeyErrors when a key is missing?

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or

...

I was under the impression that the 'or' operator was handling this
in case one operand was failing but its not the case here.


"f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
if "f(x)" returns a false value and "g(x)" raises an exception.


Then i thought of os.environ.get() to default to something but then
again we have 3 operand in the expression.


Adapt this:

>>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
'catchall'

Or nest the calls this way if an empty string is a valid value:

>>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
''

This will compute the default values even when they are not used.


I'am sorry but i do not understand the last statements at all so i
can have chnace to adapt them.


Do you know what {} is?

Do you know what {}.get('foo') is?

Do you know what x.get('foo') is if x is {}?

Do you know what {'empty':''}.get('empty') is?

Do you know what {'empty':''}.get('fruit') is?

Do you know what (None or '' or 'catchall') is?

Do you know what {}.get('foo', 'bar') is?

Do you know what {}.get('foo', {}.get('bar', 'huh')) is?

Do you know what ('foo'[3] or 'else') does?

Do you know what ('foo' or 'else'[5]) does?

Do you know how to launch an interactive Python session where you can
play with such expressions until you get the hang of it? There is no
substitute for that experience.

Do you know that you can ask for help({}.get) or help(dict.get) or
even help(os.environ.get) during such an interactive Python session,
and Python (unlike Macbeth's spirits from the vasty deep) will answer?


You dont have to be ironic. I dont have the experience you do.

Up until now i have this:

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or "Άγνωστη Πόλη"


can this be written as:

city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP',
os.environ['REMOTE_ADDR'] )) or "Άγνωστη Πόλη"

It makes it more easily for me to understand this way.


Let me try be more specific:

i want to switch this:

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or "Άγνωστη Πόλη"

host = socket.gethostbyaddr( os.environ['HTTP_CF_CONNECTING_IP'] )[0] or
socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0] or "Άγνωστη Προέλευση"

because it raises KeyError exceptions to this:

city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP',
'REMOTE_ADDR') )or "Άγνωστη Πόλη"

host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP',
'REMOTE_ADDR') )[0] or "Άγνωστη Προέλευση"

But that doesnt seem to also work.
I want to use the get method because i know if it doesnt does detect a
dictionary key item than default back what we give it.


Can you please tell me why my alternative fails to work although i'am 
using the .get method to default to something?

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Re: Handling 3 operands in an expression without raising an exception

[Nobody]

On Thu, 26 Sep 2013 10:26:48 +0300, Νίκος wrote:

> How can i wrote the two following lines so for NOT to throw out
> KeyErrors when a key is missing?
> 
> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
> gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
> "Άγνωστη Πόλη"

tz = None
ip = os.environ.get('HTTP_CF_CONNECTING_IP')
if ip:
  tz = gi.time_zone_by_addr(ip)
if not tz:
  ip = os.environ.get('REMOTE_ADDR')
  if ip:
tz = gi.time_zone_by_addr(ip)
if not tz:
  tz = "ÎγνÏÏÏη Î Ïλη"

Likewise for the hostname.

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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 11:39 πμ, ο/η Νίκος έγραψε:

Στις 26/9/2013 11:12 πμ, ο/η Jussi Piitulainen έγραψε:

Νίκος writes:


Σ�ις 26/9/2013 10:48 πμ, ο/η Jussi Piitulainen
έγ�α�ε: > ί�ος writes:



How can i wrote the two following lines so for NOT to throw out
KeyErrors when a key is missing?

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or

...

I was under the impression that the 'or' operator was handling this
in case one operand was failing but its not the case here.


"f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
if "f(x)" returns a false value and "g(x)" raises an exception.


Then i thought of os.environ.get() to default to something but then
again we have 3 operand in the expression.


Adapt this:

>>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
'catchall'

Or nest the calls this way if an empty string is a valid value:

>>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
''

This will compute the default values even when they are not used.


I'am sorry but i do not understand the last statements at all so i
can have chnace to adapt them.


Do you know what {} is?

Do you know what {}.get('foo') is?

Do you know what x.get('foo') is if x is {}?

Do you know what {'empty':''}.get('empty') is?

Do you know what {'empty':''}.get('fruit') is?

Do you know what (None or '' or 'catchall') is?

Do you know what {}.get('foo', 'bar') is?

Do you know what {}.get('foo', {}.get('bar', 'huh')) is?

Do you know what ('foo'[3] or 'else') does?

Do you know what ('foo' or 'else'[5]) does?

Do you know how to launch an interactive Python session where you can
play with such expressions until you get the hang of it? There is no
substitute for that experience.

Do you know that you can ask for help({}.get) or help(dict.get) or
even help(os.environ.get) during such an interactive Python session,
and Python (unlike Macbeth's spirits from the vasty deep) will answer?


You dont have to be ironic. I dont have the experience you do.

Up until now i have this:

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or "Άγνωστη Πόλη"


can this be written as:

city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP',
os.environ['REMOTE_ADDR'] )) or "Άγνωστη Πόλη"

It makes it more easily for me to understand this way.


Let me try be more specific:

i want to switch this:

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or 
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or "Άγνωστη Πόλη"


host = socket.gethostbyaddr( os.environ['HTTP_CF_CONNECTING_IP'] )[0] or 
socket.gethostbyaddr( os.environ['REMOTE_ADDR'] )[0] or "Άγνωστη Προέλευση"


because it raises KeyError exceptions to this:

city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP', 
'REMOTE_ADDR') )or "Άγνωστη Πόλη"


host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP', 
'REMOTE_ADDR') )[0] or "Άγνωστη Προέλευση"


But that doesnt seem to also work.
I want to use the get method because i know if it doesnt does detect a 
dictionary key item than default back what we give it.

--
https://mail.python.org/mailman/listinfo/python-list

Re: Handling 3 operands in an expression without raising an exception

[Jussi Piitulainen]

Νίκος writes:

> Σ�ις 26/9/2013 11:12 πμ, ο/η Jussi Piitulainen
> έγ�α�ε: > ί�ος writes:
> >
> >> Σ�ις 26/9/2013 10:48 πμ, ο/η Jussi Piitulainen
> >> έγ�α�ε: > ί�ος writes:
> >>>
>  How can i wrote the two following lines so for NOT to throw out
>  KeyErrors when a key is missing?
> 
>  city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
> >>> ...
>  I was under the impression that the 'or' operator was handling this
>  in case one operand was failing but its not the case here.
> >>>
> >>> "f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
> >>> if "f(x)" returns a false value and "g(x)" raises an exception.
> >>>
>  Then i thought of os.environ.get() to default to something but then
>  again we have 3 operand in the expression.
> >>>
> >>> Adapt this:
> >>>
> >>> >>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
> >>> 'catchall'
> >>>
> >>> Or nest the calls this way if an empty string is a valid value:
> >>>
> >>> >>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
> >>> ''
> >>>
> >>> This will compute the default values even when they are not used.
> >>
> >> I'am sorry but i do not understand the last statements at all so i
> >> can have chnace to adapt them.
> >
> > Do you know what {} is?
> >
> > Do you know what {}.get('foo') is?
> >
> > Do you know what x.get('foo') is if x is {}?
> >
> > Do you know what {'empty':''}.get('empty') is?
> >
> > Do you know what {'empty':''}.get('fruit') is?
> >
> > Do you know what (None or '' or 'catchall') is?
> >
> > Do you know what {}.get('foo', 'bar') is?
> >
> > Do you know what {}.get('foo', {}.get('bar', 'huh')) is?
> >
> > Do you know what ('foo'[3] or 'else') does?
> >
> > Do you know what ('foo' or 'else'[5]) does?
> >
> > Do you know how to launch an interactive Python session where you can
> > play with such expressions until you get the hang of it? There is no
> > substitute for that experience.
> >
> > Do you know that you can ask for help({}.get) or help(dict.get) or
> > even help(os.environ.get) during such an interactive Python session,
> > and Python (unlike Macbeth's spirits from the vasty deep) will answer?
>
> You dont have to be ironic. I dont have the experience you do.

Not ironic. Such questions really are how I learn and test my own
understanding, and all of the questions above are tailored to your
current specific problem. They are meant to help you.

But you should know the answers to such questions, even if you learn
them in some altogether different way. This is basic stuff.

> Up until now i have this:
> 
> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
> gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
> "�γν���η Π�λη"
> 
> 
> can this be written as:
> 
> city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP',
> os.environ['REMOTE_ADDR'] )) or "�γν���η
> Π�λη"
> 
> It makes it more easily for me to understand this way.

That will always get os.environ['REMOTE_ADDR'] and raise exception if
it doesn't exist.

Maybe you want this:

city = gi.time_zone_by_addr(os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR') or
"�γν·Π�λη")

Though I would prefer a narrower layout this way:

something = ( os.environ.get('HTTP_CF_CONNECTING_IP') or
  os.environ.get('REMOTE_ADDR') or
  "�γν·Π�λη" )
city = gi.time_zone_by_addr(something)
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Re: Handling 3 operands in an expression without raising an exception

[Antoon Pardon]

Op 26-09-13 10:39, Νίκος schreef:
> Στις 26/9/2013 11:12 πμ, ο/η Jussi Piitulainen έγραψε:
>> Νίκος writes:
>>
>>> Σ�ις 26/9/2013 10:48 πμ, ο/η Jussi Piitulainen
>>> έγ�α�ε: > ί�ος writes:

> How can i wrote the two following lines so for NOT to throw out
> KeyErrors when a key is missing?
>
> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
 ...
> I was under the impression that the 'or' operator was handling this
> in case one operand was failing but its not the case here.

 "f(x) or g(x)" raises an exception if "f(x)" raises an exception, or
 if "f(x)" returns a false value and "g(x)" raises an exception.

> Then i thought of os.environ.get() to default to something but then
> again we have 3 operand in the expression.

 Adapt this:

 >>> {}.get('foo') or {'empty':''}.get('empty') or 'catchall'
 'catchall'

 Or nest the calls this way if an empty string is a valid value:

 >>> {}.get('foo', {'empty':''}.get('empty', 'catchall'))
 ''

 This will compute the default values even when they are not used.
>>>
>>> I'am sorry but i do not understand the last statements at all so i
>>> can have chnace to adapt them.
>>
>> Do you know what {} is?
>>
>> Do you know what {}.get('foo') is?
>>
>> Do you know what x.get('foo') is if x is {}?
>>
>> Do you know what {'empty':''}.get('empty') is?
>>
>> Do you know what {'empty':''}.get('fruit') is?
>>
>> Do you know what (None or '' or 'catchall') is?
>>
>> Do you know what {}.get('foo', 'bar') is?
>>
>> Do you know what {}.get('foo', {}.get('bar', 'huh')) is?
>>
>> Do you know what ('foo'[3] or 'else') does?
>>
>> Do you know what ('foo' or 'else'[5]) does?
>>
>> Do you know how to launch an interactive Python session where you can
>> play with such expressions until you get the hang of it? There is no
>> substitute for that experience.
>>
>> Do you know that you can ask for help({}.get) or help(dict.get) or
>> even help(os.environ.get) during such an interactive Python session,
>> and Python (unlike Macbeth's spirits from the vasty deep) will answer?
>>
> You dont have to be ironic. I dont have the experience you do.

That is irrelevant. For the responsibility you have taken upon yourself,
it seems you should have experience enough to figure this out. If you
can't, you just are not up for the job.

> Up until now i have this:
> 
> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
> gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or "Άγνωστη Πόλη"
> 
> 
> can this be written as:
> 
> city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP',
> os.environ['REMOTE_ADDR'] )) or "Άγνωστη Πόλη"
> 
> It makes it more easily for me to understand this way.

Experiment and find out for yourself. That is the only way you will
acquire the experience and understanding you need. Sure we could
spoon feed you the line you need, but that will only result in you
using that line without any understanding of what you are doing so
that if in a few months time something goes wrong, you again will
have no understanding of what goes on and still will have no clue
on how to handle a problem.

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Re: Handling 3 operands in an expression without raising an exception

[Jussi Piitulainen]

Νίκος writes:

> > because it raises KeyError exceptions to this:
> >
> > city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP',
> > 'REMOTE_ADDR') )or "�γν���η Π�λη"
> >
> > host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP',
> > 'REMOTE_ADDR') )[0] or "�γν���η Π�οέλε���η"
> >
> > But that doesnt seem to also work.
> > I want to use the get method because i know if it doesnt does detect a
> > dictionary key item than default back what we give it.
> 
> Can you please tell me why my alternative fails to work although i'am
> using the .get method to default to something?

I lost connection.

Absent HTTP_CF_CONNECTING_IP in os.environ, these reduce to

city = ( gi.time_zone_by_addr('REMOTE_ADDR') or
 "�γν���η Π�λη" )

host = ( socket.gethostbyaddr('REMOTE_ADDR')[0] or
 "�γν���η Π�οέλε���η" )

so maybe 'REMOTE_ADDR' is not meant to be the actual argument in those
calls. Earlier versions tried to get 'REMOTE_ADDR' from os.environ, I
think.

Try Nobody's piecemeal approach, maybe.
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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 12:07 μμ, ο/η Antoon Pardon έγραψε:

Experiment and find out for yourself. That is the only way you will
acquire the experience and understanding you need. Sure we could
spoon feed you the line you need, but that will only result in you
using that line without any understanding of what you are doing so
that if in a few months time something goes wrong, you again will
have no understanding of what goes on and still will have no clue
on how to handle a problem.


I have tried code and also provided alternative code to solve my problem 
which also doesn't solve it.


So, you cannot accuse me that i'm not trying, that would be the case to 
just ask for a line without trying anything for myself, which i did twice.


Then i got entirely stuck and i had to ask to get unstuck.

Also when a solution is being provided to me i do not only want to use 
it but want to understand too, so if something similar comes up i will 
be in a position to solve it that time.

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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 12:04 μμ, ο/η Jussi Piitulainen έγραψε:


Up until now i have this:

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
"�γν���η Π�λη"


can this be written as:

city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP',
os.environ['REMOTE_ADDR'] )) or "�γν���η
Π�λη"

It makes it more easily for me to understand this way.


That will always get os.environ['REMOTE_ADDR'] and raise exception if
it doesn't exist.

Maybe you want this:

city = gi.time_zone_by_addr(os.environ.get('HTTP_CF_CONNECTING_IP') or
 os.environ.get('REMOTE_ADDR') or
 "�γν·Π�λη")


Okey that indeed doesn't hit on that lines.

Now my statements are as follows:

city = gi.time_zone_by_addr( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR') or "Άγνωστη Πόλη" )


host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )


So you include everything in aprenthseis with a get method that you know 
beforehand it will not raise an exception but continue to check the next 
operand and the next until it default to the string.


Its more clear this way: but look. this way now produced a weird error 
few line slater when 'host' is tryign to be identefied by 're'.


[Thu Sep 26 09:44:39 2013] [error] [client 108.162.250.63]   File 
"/home/nikos/public_html/cgi-bin/metrites.py", line 181, in 
[Thu Sep 26 09:44:39 2013] [error] [client 108.162.250.63] if not 
vip and re.search( 
r'(msn|gator|amazon|yandex|reverse|who|cloudflare|fetch|barracuda|spider|google|crawl|pingdom)', 
host ) is None:
[Thu Sep 26 09:44:39 2013] [error] [client 108.162.250.63]   File 
"/usr/local/bin/python/lib/python3.3/re.py", line 161, in search
[Thu Sep 26 09:44:39 2013] [error] [client 108.162.250.63] return 
_compile(pattern, flags).search(string)
[Thu Sep 26 09:44:39 2013] [error] [client 108.162.250.63] TypeError: 
expected string or buffer


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Re: Handling 3 operands in an expression without raising an exception

[Maarten]

On Thursday, September 26, 2013 11:31:29 AM UTC+2, Ferrous Cranus wrote:

> I have tried code and also provided alternative code to solve my problem 
> which also doesn't solve it.
> 
> So, you cannot accuse me that i'm not trying, that would be the case to 
> just ask for a line without trying anything for myself, which i did twice.

I'll accuse you of being a dimwit. The questions you ask do not show you 
trying. The code that _is_ posted is not straightforward or geared towards 
readability.

> Also when a solution is being provided to me i do not only want to use 
> it but want to understand too, so if something similar comes up i will 
> be in a position to solve it that time.

If you really want to do that, then why do you insist on one-liners? Write out 
the logic with a sequence of if statements. That is easy to understand, gives 
clearer error messages. The solution by Nobody is fairly foolproof, and the 
logic is clear. What's not to like? 

Maarten
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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 11:55 πμ, ο/η Nobody έγραψε:

On Thu, 26 Sep 2013 10:26:48 +0300, Νίκος wrote:


How can i wrote the two following lines so for NOT to throw out
KeyErrors when a key is missing?

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
"Άγνωστη Πόλη"


tz = None
ip = os.environ.get('HTTP_CF_CONNECTING_IP')
if ip:
   tz = gi.time_zone_by_addr(ip)
if not tz:
   ip = os.environ.get('REMOTE_ADDR')
   if ip:
 tz = gi.time_zone_by_addr(ip)
if not tz:
   tz = "ÎγνÏÏÏη Î Ïλη"

Likewise for the hostname.



Its logic is simple and straightforward but too many lines:

host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )


this is much better in my opinion and straighforward also and more clear 
to read:


it doens't work though:

ima thinkin that the [0] is missign at the end so i cna grab the first 
item of the returnign tuple:


host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]


for the first two element if they are beign return i cna understand the 
[0] at the end but what about if the string is being return wouldnt that 
return just the 'A' of the string?


Is it correct to write it liek this?


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Re: Handling 3 operands in an expression without raising an exception

[Antoon Pardon]

Op 26-09-13 11:31, Νίκος schreef:
> Στις 26/9/2013 12:07 μμ, ο/η Antoon Pardon έγραψε:
>> Experiment and find out for yourself. That is the only way you will
>> acquire the experience and understanding you need. Sure we could
>> spoon feed you the line you need, but that will only result in you
>> using that line without any understanding of what you are doing so
>> that if in a few months time something goes wrong, you again will
>> have no understanding of what goes on and still will have no clue
>> on how to handle a problem.
> 
> I have tried code and also provided alternative code to solve my problem
> which also doesn't solve it.

Have you tried with some kind of understanding of what you are doing or
did you just tried variations of examples you saw somewhere?

> So, you cannot accuse me that i'm not trying, that would be the case to
> just ask for a line without trying anything for myself, which i did twice.

That seems totally insufficient.

> Then i got entirely stuck and i had to ask to get unstuck.

That is your problem. You are putting all your energy in trying to
get unstuck instead of in learning so that you gain enough understanding
to get yourself unstuck.

> Also when a solution is being provided to me i do not only want to use
> it but want to understand too, so if something similar comes up i will
> be in a position to solve it that time.

You have shown no evidence that this is how you operate in reality. You
like to paint yourself like this, but in reality people still have to
explain to you that when you encouter a syntax error, you may have to
look at previous lines, while that was already explained to you a
number of times. You have a history of coming with the same kind of
problem than previous once that were solved and explained to you.

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Re: Handling 3 operands in an expression without raising an exception

[Antoon Pardon]

Op 26-09-13 11:56, Νίκος schreef:
> Στις 26/9/2013 11:55 πμ, ο/η Nobody έγραψε:
>> On Thu, 26 Sep 2013 10:26:48 +0300, Νίκος wrote:
>>
>>> How can i wrote the two following lines so for NOT to throw out
>>> KeyErrors when a key is missing?
>>>
>>> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
>>> gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
>>> "Άγνωστη Πόλη"
>>
>> tz = None
>> ip = os.environ.get('HTTP_CF_CONNECTING_IP')
>> if ip:
>>tz = gi.time_zone_by_addr(ip)
>> if not tz:
>>ip = os.environ.get('REMOTE_ADDR')
>>if ip:
>>  tz = gi.time_zone_by_addr(ip)
>> if not tz:
>>tz = "ÎγνÏÏÏη Î Ïλη"
>>
>> Likewise for the hostname.
>>
> 
> Its logic is simple and straightforward but too many lines:
> 
> host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )
> 
> this is much better in my opinion and straighforward also and more clear
> to read:

No it is not and you prove that in the very next line.

> it doens't work though:

If it doesn't do what you think it should do then it is not straight
forward or clear, at least not to you.

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Re: Referrer key missing form os.environ dictionary?

[Robert Kern]

On 2013-09-26 04:25, Chris Angelico wrote:

On Thu, Sep 26, 2013 at 11:32 AM, Terry Reedy  wrote:

Since CGI uses stdout for the finished product, it could have used stdin for
the input.


Haven't used CGI in years, but I thought POST data came on stdin?


You could just put the whole HTTP request, headers and body, through stdin and 
just make the program parse them apart.


--
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"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco

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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 1:12 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 11:56, Νίκος schreef:

Στις 26/9/2013 11:55 πμ, ο/η Nobody έγραψε:

On Thu, 26 Sep 2013 10:26:48 +0300, Νίκος wrote:


How can i wrote the two following lines so for NOT to throw out
KeyErrors when a key is missing?

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
"Άγνωστη Πόλη"


tz = None
ip = os.environ.get('HTTP_CF_CONNECTING_IP')
if ip:
tz = gi.time_zone_by_addr(ip)
if not tz:
ip = os.environ.get('REMOTE_ADDR')
if ip:
  tz = gi.time_zone_by_addr(ip)
if not tz:
tz = "ÎγνÏÏÏη Î Ïλη"

Likewise for the hostname.



Its logic is simple and straightforward but too many lines:

host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )

this is much better in my opinion and straighforward also and more clear
to read:


No it is not and you prove that in the very next line.


it doens't work though:


If it doesn't do what you think it should do then it is not straight
forward or clear, at least not to you.


It is far better than the ifs, even easier to read, i was just missing a 
[0] at the end.


host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]


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Re: What minimum should a person know before saying "I know Python"

[Schneider]

I would say it's a little bit more:
You have to know the keywords and (basic) concepts, e.g. you really have 
to understand what it means, that everything is a class.
If you get foreign, you have to be able to understand it. And the other 
way round, given a problem, you should be able to write a working solution.


bg
Johannes

On 09/20/2013 06:23 PM, Mark Janssen wrote:

I started Python 4 months ago. Largely self-study with use of Python 
documentation, stackoverflow and google. I was thinking what is the minimum 
that I must know before I can say that I know Python?

Interesting.  I would say that you must know the keywords, how to make
a Class, how to write a loop.  That covers about 85% of it.



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Re: Handling 3 operands in an expression without raising an exception

[Antoon Pardon]

Op 26-09-13 12:18, Νίκος schreef:
> Στις 26/9/2013 1:12 μμ, ο/η Antoon Pardon έγραψε:
>> Op 26-09-13 11:56, Νίκος schreef:
>>> Στις 26/9/2013 11:55 πμ, ο/η Nobody έγραψε:
 On Thu, 26 Sep 2013 10:26:48 +0300, Νίκος wrote:

> How can i wrote the two following lines so for NOT to throw out
> KeyErrors when a key is missing?
>
> city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
> gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
> "Άγνωστη Πόλη"

 tz = None
 ip = os.environ.get('HTTP_CF_CONNECTING_IP')
 if ip:
 tz = gi.time_zone_by_addr(ip)
 if not tz:
 ip = os.environ.get('REMOTE_ADDR')
 if ip:
   tz = gi.time_zone_by_addr(ip)
 if not tz:
 tz = "ÎγνÏÏÏη Î Ïλη"

 Likewise for the hostname.

>>>
>>> Its logic is simple and straightforward but too many lines:
>>>
>>> host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
>>> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )
>>>
>>> this is much better in my opinion and straighforward also and more clear
>>> to read:
>>
>> No it is not and you prove that in the very next line.
>>
>>> it doens't work though:
>>
>> If it doesn't do what you think it should do then it is not straight
>> forward or clear, at least not to you.
> 
> It is far better than the ifs, even easier to read, i was just missing a
> [0] at the end.
> 
> host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]

No it is not. Your purpose was to have a line that wouldn't throw an
exception even if some environ variables were not available. That
means it shouldn't throw an exception when I execute the code. Guess
what happens:

>>> socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
Traceback (most recent call last):
  File "", line 1, in 
socket.gaierror: [Errno -2] Name or service not known

You are just illustrating your lack of basic understaning.

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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 1:41 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 12:18, Νίκος schreef:

Στις 26/9/2013 1:12 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 11:56, Νίκος schreef:

Στις 26/9/2013 11:55 πμ, ο/η Nobody έγραψε:

On Thu, 26 Sep 2013 10:26:48 +0300, Νίκος wrote:


How can i wrote the two following lines so for NOT to throw out
KeyErrors when a key is missing?

city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] ) or
gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] ) or
"Άγνωστη Πόλη"


tz = None
ip = os.environ.get('HTTP_CF_CONNECTING_IP')
if ip:
 tz = gi.time_zone_by_addr(ip)
if not tz:
 ip = os.environ.get('REMOTE_ADDR')
 if ip:
   tz = gi.time_zone_by_addr(ip)
if not tz:
 tz = "ÎγνÏÏÏη Î Ïλη"

Likewise for the hostname.



Its logic is simple and straightforward but too many lines:

host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )

this is much better in my opinion and straighforward also and more clear
to read:


No it is not and you prove that in the very next line.


it doens't work though:


If it doesn't do what you think it should do then it is not straight
forward or clear, at least not to you.


It is far better than the ifs, even easier to read, i was just missing a
[0] at the end.

host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]


No it is not. Your purpose was to have a line that wouldn't throw an
exception even if some environ variables were not available. That
means it shouldn't throw an exception when I execute the code. Guess
what happens:


socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or

os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
Traceback (most recent call last):
   File "", line 1, in 
socket.gaierror: [Errno -2] Name or service not known

You are just illustrating your lack of basic understaning.


I'm surepirsed, becaus eon my domain [superhost.gr] the same lien of 
code works withnout an error and it display the 'host' fileds properly.


Perhaps its failing via shell or you do not have a web server installed 
to prepare the enviromental variables or i dont know what else to hink.


But in my website this code runs at the probelm with no problem.

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Re: Handling 3 operands in an expression without raising an exception

[James Harris]

"?"  wrote in message 
news:l20utg$278$1...@dont-email.me...
>  26/9/2013 12:07 ??, ?/? Antoon Pardon ??:
>> Experiment and find out for yourself. That is the only way you will
>> acquire the experience and understanding you need. Sure we could
>> spoon feed you the line you need, but that will only result in you
>> using that line without any understanding of what you are doing so
>> that if in a few months time something goes wrong, you again will
>> have no understanding of what goes on and still will have no clue
>> on how to handle a problem.
>
> I have tried code and also provided alternative code to solve my problem 
> which also doesn't solve it.
>
> So, you cannot accuse me that i'm not trying, that would be the case to 
> just ask for a line without trying anything for myself, which i did twice.

Agreed. You did post the work you had already done which seems reasonable to 
me.

For your first example, because you are worried about key errors maybe you 
could code something like the following.

  try:
city = gi.time_zone_by_addr( os.environ['HTTP_CF_CONNECTING_IP'] )
  except KeyError:
try:
  city = gi.time_zone_by_addr( os.environ['REMOTE_ADDR'] )
except KeyError:
  city = "??? "

Does that help?

James


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Re: Handling 3 operands in an expression without raising an exception

[Antoon Pardon]

Op 26-09-13 12:51, Νίκος schreef:
> Στις 26/9/2013 1:41 μμ, ο/η Antoon Pardon έγραψε:
>> Op 26-09-13 12:18, Νίκος schreef:
>>> Στις 26/9/2013 1:12 μμ, ο/η Antoon Pardon έγραψε:
 Op 26-09-13 11:56, Νίκος schreef:
>>>
>>> It is far better than the ifs, even easier to read, i was just missing a
>>> [0] at the end.
>>>
>>> host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
>>> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
>>
>> No it is not. Your purpose was to have a line that wouldn't throw an
>> exception even if some environ variables were not available. That
>> means it shouldn't throw an exception when I execute the code. Guess
>> what happens:
>>
> socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
>> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
>> Traceback (most recent call last):
>>File "", line 1, in 
>> socket.gaierror: [Errno -2] Name or service not known
>>
>> You are just illustrating your lack of basic understaning.
> 
> I'm surepirsed, becaus eon my domain [superhost.gr] the same lien of
> code works withnout an error and it display the 'host' fileds properly.

You shoudn't be. This illustrates beautifully the difference between
understanding what one is doing and dabbling around until one stumbles
on something that currently works but that will stop working in other
circumstances.

> Perhaps its failing via shell or you do not have a web server installed
> to prepare the enviromental variables or i dont know what else to hink.

Yes it is failing via shell, but that doesn't matter. If your purpose
was to have that line working even if the environ variables were not
available, then the line should work from a shell too.

> But in my website this code runs at the probelm with no problem.

So? That just means that your website is not a good test environment
for checking whether the code works under all circumstances you want
it to work.

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Re: Handling 3 operands in an expression without raising an exception

[Dave Angel]

On 26/9/2013 06:51, Νίκος wrote:

   
> socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
>> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
>> Traceback (most recent call last):
>>File "", line 1, in 
>> socket.gaierror: [Errno -2] Name or service not known
>>
>> You are just illustrating your lack of basic understaning.
>
> I'm surepirsed, becaus eon my domain [superhost.gr] the same lien of 
> code works withnout an error and it display the 'host' fileds properly.
>
> Perhaps its failing via shell or you do not have a web server installed 
> to prepare the enviromental variables or i dont know what else to hink.
>
> But in my website this code runs at the probelm with no problem.
>
In Python 3.3, but not on a web server, I get:


>>> import socket
>>> socket.gethostbyaddr("unknown")[0]
Traceback (most recent call last):
  File "", line 1, in 
socket.gaierror: [Errno -2] Name or service not known
>>> 

Question, do you get the same result on your server?  (You can put the
Greek string in place of "unknown" of course)

If so, then the default value makes no sense;  it'll cause an exception
if it's ever used.  If you insist on sticking to expressions (no
try/catch, no if statements), then perhaps you should default to a
string representing a domain which will always exist.

-- 
DaveA


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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 2:07 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 12:51, Νίκος schreef:

Στις 26/9/2013 1:41 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 12:18, Νίκος schreef:

Στις 26/9/2013 1:12 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 11:56, Νίκος schreef:


It is far better than the ifs, even easier to read, i was just missing a
[0] at the end.

host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]


No it is not. Your purpose was to have a line that wouldn't throw an
exception even if some environ variables were not available. That
means it shouldn't throw an exception when I execute the code. Guess
what happens:


socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or

os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
Traceback (most recent call last):
File "", line 1, in 
socket.gaierror: [Errno -2] Name or service not known

You are just illustrating your lack of basic understaning.


I'm surepirsed, becaus eon my domain [superhost.gr] the same lien of
code works withnout an error and it display the 'host' fileds properly.


You shoudn't be. This illustrates beautifully the difference between
understanding what one is doing and dabbling around until one stumbles
on something that currently works but that will stop working in other
circumstances.


Perhaps its failing via shell or you do not have a web server installed
to prepare the enviromental variables or i dont know what else to hink.


Yes it is failing via shell, but that doesn't matter. If your purpose
was to have that line working even if the environ variables were not
available, then the line should work from a shell too.


But in my website this code runs at the probelm with no problem.


So? That just means that your website is not a good test environment
for checking whether the code works under all circumstances you want
it to work.


Okey then please tell me, what do you see wrong in it:

socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]

the [0] at then end in case the statemnt default to the string?
please tell me in details what might go wrong with it so i cna 
understand it.

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Re: Handling 3 operands in an expression without raising an exception

[Antoon Pardon]

Op 26-09-13 13:25, Νίκος schreef:
>>
> Okey then please tell me, what do you see wrong in it:
> 
> socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
> 
> the [0] at then end in case the statemnt default to the string?
> please tell me in details what might go wrong with it so i cna
> understand it.

Startup python and try to figure it out yourself. Show us you can
really learn something.

-- 
Antoon Pardon

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Re: Convert namedtuple to dictionary

[Tim Chase]

On 2013-09-26 01:08, Steven D'Aprano wrote:
> On Wed, 25 Sep 2013 18:41:25 -0500, Tim Chase wrote about
> namedtuple:
> 
> > While it uses the "private" member-variable "_fields", you can do
> 
> It's not actually private!
> 
> namedtuple is documented as an exception to the rule that methods 
> starting with a single leading underscore are private. Named tuples 
> define three public methods and one data attribute. In order to
> avoid clashing with field names, they start with a single
> underscore, but they are documented as public:
> 
> _make
> _asdict
> _replace
> _fields

Well dang if "leading underscore suggests private/internal use"
convention got tossed out the window here :)

But indeed, they are in the docs, so (to the OP), use _asdict() and
make life easy.

-tkc



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Problem when installing Boost.Python

[Wenlong Wang]

Hi, All



I'm not sure if am asking in the right place, but since this is Python
related, I'd like to try it out.



My setup is Windows7 64-bit, Python 2.7 64bit, Boost 1.54, Visual Studio
2012 Express Version 64bit.



I am a beginner of Python, and am trying to bridge Python and C++. Thus
I download the Boost library.



I followed the instruction here:
http://www.boost.org/doc/libs/1_54_0/more/getting_started/windows.html



And successfully installed the Basic Boost.



Then I found that Boost.Python requires a separately installation,
according to another instruction here:



http://www.boost.org/doc/libs/1_54_0/libs/python/doc/building.html



I am stuck at step 3.1.4 where the instruction says to run a example:



4.  Invoke bjam. Replace the "stage" argument from the example
invocation from section 5 of the Getting Started Guide

with "test," to build all the test targets. Also add the argument
"--verbose-test" to see the output generated by the tests when they are
run.

On Windows, your bjam invocation might look something like:

C:\boost_1_34_0\...\quickstart> bjam toolset=msvc --verbose-test test


When I input the command line above, I have 135 unresolved external
errors! One of them is like follows:



exec.obj : error LNK2019: unresolved external symbol
__imp__PyEval_GetGlobals referenced in function

"class boost::python::api::object __cdecl boost::python::eval(class
boost::python::str,class boost::python::api::object,

class
boost::python::api::object)"(?eval@python@boost@@YA?AVobject@api@12@Vstr
@12@V3412@1@Z)

..\..\..\..\bin.v2\libs\python\build\msvc-11.0\debug\boost_python-vc110-
gd-1_54.dll



I know this is more C++, however, I guess someone in this mailing list
may have experienced with Boost.Python. My apologies if this mail
bothers you.



Can anyone help me to work around this?



Thank you!



Regards

Long


 
Wenlong Wang
Risk Analyst, Capquest Group Ltd

Email: ww...@capquest.co.uk
Fleet 27, Rye Close, Fleet, GU51 2QQ.
Website: http://www.capquest.co.uk/
 
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and Wales with their registered offices at Fleet 27, Rye Close, Fleet, 
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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 2:24 μμ, ο/η Dave Angel έγραψε:

On 26/9/2013 06:51, Νίκος wrote:



socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or

os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )[0]
Traceback (most recent call last):
File "", line 1, in 
socket.gaierror: [Errno -2] Name or service not known

You are just illustrating your lack of basic understaning.


I'm surepirsed, becaus eon my domain [superhost.gr] the same lien of
code works withnout an error and it display the 'host' fileds properly.

Perhaps its failing via shell or you do not have a web server installed
to prepare the enviromental variables or i dont know what else to hink.

But in my website this code runs at the probelm with no problem.


In Python 3.3, but not on a web server, I get:



import socket
socket.gethostbyaddr("unknown")[0]

Traceback (most recent call last):
   File "", line 1, in 
socket.gaierror: [Errno -2] Name or service not known




Question, do you get the same result on your server?  (You can put the
Greek string in place of "unknown" of course)

If so, then the default value makes no sense;  it'll cause an exception
if it's ever used.  If you insist on sticking to expressions (no
try/catch, no if statements), then perhaps you should default to a
string representing a domain which will always exist.


Yes, you are right, in my shell it fails too givign the same error 
message as yours, while on the other had in the websste is working.


Can you explain this please?
why doesnt it fail to both enviroments?

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Re: Extracting lines from text files - script with a couple of 'side effects'

[mstagliamonte]

Hi,

Thanks for the answers! And Dave, thanks for explaining the cause of the 
problem I will keep that in mind for the future. You're right, I am doing the 
search backward, it just seemed easier for me to do it in that way. Looks like 
I need to keep practising...

Both your suggestions work, I will try and learn from them.

Have a nice day
Max
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Re: Handling 3 operands in an expression without raising an exception

[Antoon Pardon]

Op 26-09-13 14:39, Νίκος schreef:
> Yes, you are right, in my shell it fails too givign the same error
> message as yours, while on the other had in the websste is working.
> 
> Can you explain this please?
> why doesnt it fail to both enviroments?

Your site and your shell are two different environments. The state
of the website environment lets your code succeed while the state
of the shell environment, doesn't.

-- 
Antoon Pardon

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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 3:53 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 14:39, Νίκος schreef:

Yes, you are right, in my shell it fails too givign the same error
message as yours, while on the other had in the websste is working.

Can you explain this please?
why doesnt it fail to both enviroments?


Your site and your shell are two different environments. The state
of the website environment lets your code succeed while the state
of the shell environment, doesn't.

What modification does it need to also work in the shell environmentthe 
[0] at the end is what complicates things.

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Re: Newline interpretation issue with MIMEApplication with binary data, Python 3.3.2

[Neil Cerutti]

On 2013-09-26, Chris Angelico  wrote:
> On Thu, Sep 26, 2013 at 2:23 PM, Nils Bunger  wrote:
>> Yes, it's email.mime.MIMEApplication. I've pasted a snippet
>> with the imports below.
>>
>> I'm trying to use this to build a multi-part MIME message,
>> with this as one part.
>>
>> I really can't figure out any way to attach a binary part like
>> this to a multi-part MIME message without the encoding
>> issue... any help would be greatly appreciate!
>
> I partly responded just to ping your thread, as I'm not
> particularly familiar with the email.mime module. But a glance
> at the docs suggests that MIMEApplication is a "subclass of
> MIMENonMultipart", so might it be a problem to use that for
> multipart??
>
> It's designed to handle text, so you may want to use an encoder
> (like the default base64 one) rather than trying to push binary
> data through it.
>
> Random ideas, hopefully someone who actually knows the module
> can respond.

I got interested in it since I have never used any of the
modules. So I played with it enough to discover that the part of
the code above that converts the \r to \n is the flatten call.

I got to here and RFC 2049 and gave up.

   The following guidelines may be useful to anyone devising a data
   format (media type) that is supposed to survive the widest range of
   networking technologies and known broken MTAs unscathed.  Note that
   anything encoded in the base64 encoding will satisfy these rules, but
   that some well-known mechanisms, notably the UNIX uuencode facility,
   will not.  Note also that anything encoded in the Quoted-Printable
   encoding will survive most gateways intact, but possibly not some
   gateways to systems that use the EBCDIC character set.

(1)   Under some circumstances the encoding used for data may
  change as part of normal gateway or user agent
  operation.  In particular, conversion from base64 to
  quoted-printable and vice versa may be necessary.  This
  may result in the confusion of CRLF sequences with line
  breaks in text bodies.  As such, the persistence of
  CRLF as something other than a line break must not be
  relied on.

(2)   Many systems may elect to represent and store text data
  using local newline conventions.  Local newline
  conventions may not match the RFC822 CRLF convention --
  systems are known that use plain CR, plain LF, CRLF, or
  counted records.  The result is that isolated CR and LF
  characters are not well tolerated in general; they may
  be lost or converted to delimiters on some systems, and
  hence must not be relied on.

So putting a raw CR in a binary chunk maybe be intolerable, and
you need to use a different encoder. But I'm out of my element.

-- 
Neil Cerutti
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Re: Referrer key missing form os.environ dictionary?

[Grant Edwards]

On 2013-09-26, Steven D'Aprano  wrote:
> On Wed, 25 Sep 2013 15:18:41 +, Grant Edwards wrote:
>
>>> The Referer is not an environment variable.
>> 
>> It is when you're writing a CGI app.
>> 
>>> How would your shell know what URL you were just browsing?
>> 
>> Because the HTTP server sets those environment variables before invoking
>> the CGI app.
>
> I stand corrected.
>
> That's a pretty shitty design though, isn't it?

On a Unix system when you invoke a program, you "pass" it four things:

 1) A dictionary where keys/values are both strings [enviornment variables]
 2) A list of strings [command line args]
 3) A set of open file descriptors. 
 4) The current working directory. 

You can provide input values to the program through any of these.

For interactive programs, 2 and 3 are the most convenient. For
programs intended to be invoked non-interactively via another program
the first option can be very elegent and versatile -- but it does make
use of the program interactively rather awkward.  Semantically,
passing values to a program via environment variables is very similar
to keyword arguments to a Python function, while command line
arguments are like positional arguments to a Python function.
 
> Communicating via environment variables. What is this, 1998? :-)
>
> Mind you, I'm not sure what other alternatives exist.

Command line arguments, open file descriptors, or files in the CWD. 
All are more difficult to use programmatically than environment
variables.

-- 
Grant Edwards   grant.b.edwardsYow! I guess you guys got
  at   BIG MUSCLES from doing too
  gmail.commuch STUDYING!
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Re: Referrer key missing form os.environ dictionary?

[Grant Edwards]

On 2013-09-26, Chris Angelico  wrote:
> On Thu, Sep 26, 2013 at 11:32 AM, Terry Reedy  wrote:
>> Since CGI uses stdout for the finished product, it could have used stdin for
>> the input.
>
> Haven't used CGI in years, but I thought POST data came on stdin?

Yes.  The user data is read via stdin.  The stuff passed via the
environemnt "dictionary" is meta-data (stuff from the HTTP request
headers, and stuff synthesized by the HTTP server).

-- 
Grant Edwards   grant.b.edwardsYow! !  Now I understand
  at   advanced MICROBIOLOGY and
  gmail.comth' new TAX REFORM laws!!
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Re: Understanding how is a function evaluated using recursion

[Neil Cerutti]

On 2013-09-25, Arturo B  wrote:
> Hi, I'm doing Python exercises and I need to write a function
> to flat nested lists as this one: 
>
> [[1,2,3],4,5,[6,[7,8]]]
>
> To the result:
>
> [1,2,3,4,5,6,7,8]
>
> So I searched for example code and I found this one that uses
> recursion (that I don't understand):
>
> def flatten(l):
> ret = []
> for i in l:
> if isinstance(i, list) or isinstance(i, tuple):
> ret.extend(flatten(i)) #How is flatten(i) evaluated?
> else:
> ret.append(i)
> return ret
>
> So I know what recursion is, but I don't know how is 
>
>flatten(i)
>  
> evaluated, what value does it returns?

It only *looks* like magic, as others have explained.

I keep a file callled bikeshed.py for these occasions. The
flatten function has been to the bike shed a lot [1]. Here's a
non-recursive version of flatten for comparison:

from collections import Sequence

def flatten(seq):
stack = []
i = 0
result = []
while True:
if i >= len(seq):
if stack:
seq, i = stack.pop()
else:
return result
elif isinstance(seq[i], Sequence):
stack.append((seq, i+1)) # Store the continue point
seq = seq[i]
i = 0
else:
result.append(seq[i])
i += 1

When this version encounters a nested list, it keeps a stack of
sequences and indices to continue on with after processing the
nested list. The code at the start of the while loop, when a
sequence is exhausted, pops the continue points fromt he stack,
returning if the stack is empty.

It's simpler and cleaner to call flatten on itself, as in the
recursive version, because the stack frames do all the
bookkeeping for you. CPython has a limited number of stack frames
though, so the version above might be preferable for certain
levels of nesting.

[1] http://en.wiktionary.org/wiki/bikeshed

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Neil Cerutti
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Re: Handling 3 operands in an expression without raising an exception

[Dave Angel]

On 26/9/2013 09:34, Νίκος wrote:

> Στις 26/9/2013 3:53 μμ, ο/η Antoon Pardon έγραψε:
>> Op 26-09-13 14:39, Νίκος schreef:
>>> Yes, you are right, in my shell it fails too givign the same error
>>> message as yours, while on the other had in the websste is working.
>>>
>>> Can you explain this please?
>>> why doesnt it fail to both enviroments?
>>
>> Your site and your shell are two different environments. The state
>> of the website environment lets your code succeed while the state
>> of the shell environment, doesn't.
>>
> What modification does it need to also work in the shell environmentthe 
> [0] at the end is what complicates things.

Not at all.  What complicates/confuses things is trying to do too much
in one line.

The line is trying to solve two separate things.  You might now
understand the first of them; the fetching of multiple environment
variables that may or may not exist.

The second thing is the function call to gethostbyname().  If fed
invalid data, this call will throw an exception.  So you need to either
put it in a try/catch or somehow pretend that you can know what
constitutes invalid data.  One example of invalid data is your default
string.  Another might be if one of those environment variables exists,
but isn't reasonable.  And a third might be if the domain server
temporarily refuses to recognize a valid hostname.

I'd say you need to put the gethostbyname() in a try/catch, and then
supply some reasonable bogus string for host.  Only you will know what
to use there;  depending on what you're going to use it for.


ipval = (os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR', "Please throw a gaierror exception")
try:
 host = socket.gethostbyaddr(ipval) [0]
except socket.gaierror as exc;
 host = "Unknown host"

I don't know the gethostbyaddr(), so i don't know if there are other
exceptions you should also try to catch.

-- 
DaveA


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Re: Understanding how is a function evaluated using recursion

[Neil Cerutti]

On 2013-09-26, Neil Cerutti  wrote:
> def flatten(seq):
>
> [1] http://en.wiktionary.org/wiki/bikeshed

In that spirit, it occurs to me that given current Python
nomenclature, 'flattened' would be a better name.

-- 
Neil Cerutti
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Re: Handling 3 operands in an expression without raising an exception

[Denis McMahon]

On Thu, 26 Sep 2013 12:56:19 +0300, Νίκος wrote:

> host = socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP') or
> os.environ.get('REMOTE_ADDR') or  "Άγνωστη Προέλευση" )

Perhaps you need something that looks more like:

some_value = some_function_of( some_value ) or some_function_of
( some_value )
if some_value:
host = some_function_of( some_value )
else:
host = some_value

or even:

try:
host = some_function_of( some_function_of( some_value ) or 
some_function_of( some_value ) )
except some_error_type [ or some_error_type  ]:
host = some_value

-- 
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Re: Proposal: [... for ... while cond(x)]

[Nick Mellor]

Hi all,

It might be a risk that we create some hairy or subtle semantics, but perhaps 
this idea has legs. The 'pythonic' syntax is very attractive.

# skip the silence at the start
data = (amp for amp in signal from abs(amp) > 0.05)

# drop files that are less than 600 bytes
# (already sorted into ascending order of size)
files = (file for file in filelist from os.stat(file).st_size > 600)

# Analyse bunch of log lines up to a certain timestamp
cutoff = datetime.datetime.now() - datetime.timedelta(hours=1)
checklogs = (entry for entry in log while entry.timestamp <= cutoff)

In use it feels along the same lines as else: clauses in try/finally and for 
loops, both of which I like-- it seems natural in Python, keeps the meaning 
clear and consistent, avoids complicated, iterative, inexpressive code.

Terry Reedy wrote:
> You're right. The syntax is ambiguous. I agree it's not a good idea,
now. :)

When while, if and from are made mutually exclusive, not mixed, on a 
comprehension clause, it looks to me like the ambiguity disappears:

> x for x in xs while cond(x) if blah(x)

not legal Python-- if and while are mutually exclusive on the same 
comprehension clause. On the one hand it's like writing x for x in xs if f(x) < 
10 if g(x) > 100, the illegality of which no-one is complaining about. Just 
write:

x for x in xs while cond(x) and cond2(x)

or

x for x in xs if cond(x) and cond2(x)

If there is a need to filter using if as well as while, then use two 
comprehensions:

intermediate = [x for x in xs while cond(x)]
final = [x for x in intermediate if cond2(x)]

or the same comprehension applied to itself:

y for y in x for x in xs if cond(x) while cond2(y)

The if and the while operation *should* be kept separate-- they're different 
stages of processing the data.

> > x*y for x in xs while cond(x) for y in ys if cond(y)

legal Python-- the 'if cond(y)' unambiguously refers to the inner 
comprehension. 


> x for x in xs if blah(x) while cond(x)

not legal Python-- if and while are mutually exclusive in the same 
comprehension clause.

The objection to "while" as an abbreviation:

> e(x) for x in xs if cond(x)
> 
> is an abbreviation of
> 
> for x in xs:
>   if cond(x)
> yield e(x)
> 
> and similarly with more for and if clauses,
> whereas the analogous expansion of your proposal
> 
> for x in xs:
>   while cond(x):
>  yield e(x)
> 
> is an infinite loop and not at all what you mean.

That's because while is being used here with a different semantic to the while 
loop. It actually means:

for x in xs:
if not cond(x):
break
yield e(x)

and for 'from':


emit = False
for x in xs:
if not emit:
if cond(x):
emit = True
else:
yield e(x)


Cheers,

Nick
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Re: Handling 3 operands in an expression without raising an exception

[Denis McMahon]

On Thu, 26 Sep 2013 14:25:55 +0300, Νίκος wrote:

> Okey then please tell me, what do you see wrong in it:
> 
> socket.gethostbyaddr( os.environ.get('HTTP_CF_CONNECTING_IP')

If os.environ.get('HTTP_CF_CONNECTING_IP') is false

> or os.environ.get('REMOTE_ADDR') 

and os.environ.get('REMOTE_ADDR') is false

> or  "Άγνωστη Προέλευση" )[0]

The you try and get the host name from the ip address "Άγνωστη 
Προέλευση", but "Άγνωστη Προέλευση" is not an ip address, so you get an 
error.

-- 
Denis McMahon, denismfmcma...@gmail.com
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Re: Handling 3 operands in an expression without raising an exception

[Denis McMahon]

On Thu, 26 Sep 2013 12:56:19 +0300, Νίκος wrote:

> Its logic is simple and straightforward but too many lines:

There is no "too many lines."

> this is much better in my opinion and straighforward also and more clear
> to read ... it doens't work though:

This is just a stupid attitude for a coder to have.

-- 
Denis McMahon, denismfmcma...@gmail.com
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Re: Proposal: [... for ... while cond(x)]

[Nick Mellor]

On Friday, 27 September 2013 00:39:30 UTC+10, Nick Mellor  wrote:

[snip]
> for x in xs:
> if not emit:
> if cond(x):
> emit = True
> else:
> yield e(x)
> 

Oops!

for x in xs:
   if not emit:
   if cond(x):
   emit = True
   yield e(x)
   else:
   yield e(x)
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Download all youtube favorites with youtube-dl script

[Bill]

I have been using the script youtube-dl http://rg3.github.io/youtube-dl/

And I was wondering if there is a way to download all of a user's 
favorites or uploads.


The script has a functionality to download all videos in a txt file. So 
if there is a way using the youtube API or JSON (none of which I am 
familiar with) to bring up a list of all these videos then it'd be a 
simple case putting these urls into a file.


The problem is youtube displays favorites or user uploads in pages or 
infinite scroll. So it is difficult to access them by the BeautifulSoup 
module.



What do you suggest?
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Re: Referrer key missing form os.environ dictionary?

[Chris Angelico]

On Fri, Sep 27, 2013 at 12:11 AM, Grant Edwards  wrote:
> On a Unix system when you invoke a program, you "pass" it four things:
>
>  1) A dictionary where keys/values are both strings [enviornment variables]
>  2) A list of strings [command line args]
>  3) A set of open file descriptors.
>  4) The current working directory.
>
> You can provide input values to the program through any of these.
>
> For interactive programs, 2 and 3 are the most convenient.

Hrm, not sure about #3 for interactive programs, unless you
specifically mean the three standard streams. With most Unix shells,
you should be able to set environment variables:

PGUSER=fred PGPASSWORD=secret psql

Not as convenient as #2, but far easier than passing an open file
descriptor. Of course, passing file descriptors around is pretty easy
programmatically, but when you say "interactive" I assume you're
talking also about an interactive shell.

GUI interactions of course follow their own rules completely. In most
systems, it's really easy to invoke an application with one argument,
a file name; it's generally much harder to customize the arguments at
the keyboard. OS/2 had a facility for doing that. You just put square
brackets into the configured args and it'd turn it into a prompt:

--foo=bar --mode=[Choose mode, 1-3:] %*

You'd get a nice little popup with the prompt you specified, and
whatever you type gets put into the args. Haven't seen that in any
other system - at least, not as conveniently.

ChrisA
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Re: Download all youtube favorites with youtube-dl script

[Joel Goldstick]

On Thu, Sep 26, 2013 at 11:13 AM, Bill  wrote:

> I have been using the script youtube-dl 
> http://rg3.github.io/youtube-**dl/
>
> And I was wondering if there is a way to download all of a user's
> favorites or uploads.
>
> The script has a functionality to download all videos in a txt file. So if
> there is a way using the youtube API or JSON (none of which I am familiar
> with) to bring up a list of all these videos then it'd be a simple case
> putting these urls into a file.
>
> The problem is youtube displays favorites or user uploads in pages or
> infinite scroll. So it is difficult to access them by the BeautifulSoup
> module.
>
>
> What do you suggest?
> --
> https://mail.python.org/**mailman/listinfo/python-list
>

Have you looked at the youtube API?  That would be better than screen
scraping.  https://developers.google.com/youtube/getting_started


-- 
Joel Goldstick
http://joelgoldstick.com
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Upload Windows binaries on pypi from Linux

[Giampaolo Rodola']

I have a Python extension module (psutil) written in C which I compile for
different Python versions (from 2.4 to 3.3) and want to upload them on pypi.

The Windows machine is not connected to internet  so after I generate the
Windows binaries (via setup.py bdist_wininst) I move the .exe files from
Windows to Linux. From there I want to upload all the *.exe files on pypi.

Apparently I can automatically do this only from Windows via "setup.py
upload bdist_wininst" but as I said I have no internet connection on that
box.

Is there a way to tell setup.py to upload those *.exe file on pypi from
Linux or some tool which can do that via HTTP POST or something?

Thanks in advance,

--- Giampaolo

https://code.google.com/p/pyftpdlib/
https://code.google.com/p/psutil/
https://code.google.com/p/pysendfile/
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Re: Newline interpretation issue with MIMEApplication with binary data, Python 3.3.2

[Nils Bunger]

Hi Neil, 

Thanks for looking at this.  

I'm trying to create a multipart MIME for an HTTP POST request, not an email.  
This is for a third-party API that requires a multipart POST with a binary 
file, so I don't have the option to just use a different encoding.

Multipart HTTP is standardized in HTTP 1.0 and supports binary parts. Also, no 
one will re-interpret contents of HTTP on the wire, as binary is quite normal 
in HTTP.

The issue seems to be some parts of the python MIME encoder still assume it's 
for email only, where everything would be b64 encoded.

Maybe I have to roll my own to create a multipart msg with a binary file? I was 
hoping to avoid that.

Nils

ps. You probably know this, but in case anyone else reads this thread, HTTP 
requires all headers to have CRLF, not native line endings. The python MIME 
modules can do that properly as of python 3.2 (fixed as of this bug 
http://hg.python.org/cpython/rev/ebf6741a8d6e/)



> 
> I got interested in it since I have never used any of the
> 
> modules. So I played with it enough to discover that the part of
> 
> the code above that converts the \r to \n is the flatten call.
> 
> 
> 
> I got to here and RFC 2049 and gave up.
> 
> 
> 
>The following guidelines may be useful to anyone devising a data
> 
>format (media type) that is supposed to survive the widest range of
> 
>networking technologies and known broken MTAs unscathed.  Note that
> 
>anything encoded in the base64 encoding will satisfy these rules, but
> 
>that some well-known mechanisms, notably the UNIX uuencode facility,
> 
>will not.  Note also that anything encoded in the Quoted-Printable
> 
>encoding will survive most gateways intact, but possibly not some
> 
>gateways to systems that use the EBCDIC character set.
> 
> 
> 
> (1)   Under some circumstances the encoding used for data may
> 
>   change as part of normal gateway or user agent
> 
>   operation.  In particular, conversion from base64 to
> 
>   quoted-printable and vice versa may be necessary.  This
> 
>   may result in the confusion of CRLF sequences with line
> 
>   breaks in text bodies.  As such, the persistence of
> 
>   CRLF as something other than a line break must not be
> 
>   relied on.
> 
> 
> 
> (2)   Many systems may elect to represent and store text data
> 
>   using local newline conventions.  Local newline
> 
>   conventions may not match the RFC822 CRLF convention --
> 
>   systems are known that use plain CR, plain LF, CRLF, or
> 
>   counted records.  The result is that isolated CR and LF
> 
>   characters are not well tolerated in general; they may
> 
>   be lost or converted to delimiters on some systems, and
> 
>   hence must not be relied on.
> 
> 
> 
> So putting a raw CR in a binary chunk maybe be intolerable, and
> 
> you need to use a different encoder. But I'm out of my element.
> 
> 
> 
> -- 
> 
> Neil Cerutti
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Re: Download all youtube favorites with youtube-dl script

[Philipp Hagemeister]

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA512

Hi Bill,

the best way to ask for features or file bugs on youtube-dl is asking
us at http://github.com/rg3/youtube-dl/issues . Luckily, I this list
from time to time ;)

Simply use

youtube-dl --username u...@gmail.com --password secret :ytfav

Best,

Philipp

On 09/26/2013 05:13 PM, Bill wrote:
> I have been using the script youtube-dl
> http://rg3.github.io/youtube-dl/
> 
> And I was wondering if there is a way to download all of a user's 
> favorites or uploads.
> 
> The script has a functionality to download all videos in a txt
> file. So if there is a way using the youtube API or JSON (none of
> which I am familiar with) to bring up a list of all these videos
> then it'd be a simple case putting these urls into a file.
> 
> The problem is youtube displays favorites or user uploads in pages
> or infinite scroll. So it is difficult to access them by the
> BeautifulSoup module.
> 
> 
> What do you suggest?

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Re: Newline interpretation issue with MIMEApplication with binary data, Python 3.3.2

[Nils Bunger]

Hi all, 

I was able to workaround this problem by encoding a unique 'marker' in the 
binary part, then replacing the marker with the actual binary content after 
generating the MIME message. 

See my answer on Stack Overflow http://stackoverflow.com/a/19033750/526098 for 
the code.

Thanks, your suggestions helped me think of this.

Nils

On Wednesday, September 25, 2013 9:38:17 AM UTC-7, Nils Bunger wrote:
> Hi, 
> 
> 
> 
> I'm having trouble encoding a MIME message with a binary file.  Newline 
> characters are being interpreted even though the content is supposed to be 
> binary. This is using Python 3.3.2
> 
> 
> 
> Small test case:
> 
> 
> 
> app = MIMEApplication(b'Q\x0dQ', _encoder=encode_noop)
> 
> b = io.BytesIO()
> 
> g = BytesGenerator(b)
> 
> g.flatten(app)
> 
> for i in b.getvalue()[-3:]:
> 
> print ("%02x " % i, end="")
> 
> print ()
> 
> 
> 
> This prints 51 0a 51,  meaning the 0x0d character got reinterpreted as a 
> newline. 
> 
> 
> 
> I've tried setting an email policy of HTTP policy, but that goes even 
> further, converting \r to \r\n
> 
> 
> 
> This is for HTTP transport, so binary encoding is normal.
> 
> 
> 
> Any thoughts how I can do this properly?

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Re: Convert namedtuple to dictionary

[Virendra Tripathi]

Thx Tim. Your solution works. I am, as you can probably tell, a newbie at 
Python. 
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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 5:22 μμ, ο/η Dave Angel έγραψε:

On 26/9/2013 09:34, Νίκος wrote:


Στις 26/9/2013 3:53 μμ, ο/η Antoon Pardon έγραψε:

Op 26-09-13 14:39, Νίκος schreef:

Yes, you are right, in my shell it fails too givign the same error
message as yours, while on the other had in the websste is working.

Can you explain this please?
why doesnt it fail to both enviroments?


Your site and your shell are two different environments. The state
of the website environment lets your code succeed while the state
of the shell environment, doesn't.


What modification does it need to also work in the shell environmentthe
[0] at the end is what complicates things.


Not at all.  What complicates/confuses things is trying to do too much
in one line.

The line is trying to solve two separate things.  You might now
understand the first of them; the fetching of multiple environment
variables that may or may not exist.

The second thing is the function call to gethostbyname().  If fed
invalid data, this call will throw an exception.  So you need to either
put it in a try/catch or somehow pretend that you can know what
constitutes invalid data.  One example of invalid data is your default
string.  Another might be if one of those environment variables exists,
but isn't reasonable.  And a third might be if the domain server
temporarily refuses to recognize a valid hostname.

I'd say you need to put the gethostbyname() in a try/catch, and then
supply some reasonable bogus string for host.  Only you will know what
to use there;  depending on what you're going to use it for.


ipval = (os.environ.get('HTTP_CF_CONNECTING_IP') or
os.environ.get('REMOTE_ADDR', "Please throw a gaierror exception")
try:
  host = socket.gethostbyaddr(ipval) [0]
except socket.gaierror as exc;
  host = "Unknown host"

I don't know the gethostbyaddr(), so i don't know if there are other
exceptions you should also try to catch.



Indeed this logic you follow is hethe best i have seen so far.
But actually i have 2 variables that relay on a proper ip address.

ipval = ( os.environ.get('HTTP_CF_CONNECTING_IP') or 
os.environ.get('REMOTE_ADDR', "UnKnown Origin") )

try:
gi = pygeoip.GeoIP('/usr/local/share/GeoIPCity.dat')
city = gi.time_zone_by_addr( ipval )
host = socket.gethostbyaddr( ipval ) [0]
except socket.gaierror as e:
city = host = "UnKnown Origin"

But then what if in case of an error i needed different string set to be 
assigned on city and host respectively?


As i ahve it know in case of n address related error i get the smae 
sting for both of them.


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Re: Convert namedtuple to dictionary

[Virendra Tripathi]

Hi MRAB,

Thanks. Learning a lot thanks to you guys.

I should have mentioned that the data is dynamic, in the sense that 'brucelee' 
could be 'jackiechan' , the number of named tuples - i.e., 'brucelee(…)', could 
change as well, the next time data is pulled in. The format of the data would 
however remain the same.

I am using @Tim Chase's solution for now. 

Your solution will also work but I think I'll need to create a fn to pull out 
the " n " values as in: ">>> n = brucelee(x=123, y=321)"

Thanks,

Virendra



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Re: Convert namedtuple to dictionary

[Virendra Tripathi]

Hi Ned,

Thanks. Wouldn't I have to first create a function to pull out the 'dictdict' 
from the data? I assume 'dictdict' refers to the 'brucelee' named tuple in the 
example. That's where I was getting stuck-trying to pull out the named tuples 
from the dict and operate on it.

Thanks,

Virendra
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Re: Convert namedtuple to dictionary

[Tim Chase]

On 2013-09-26 16:42, Virendra Tripathi wrote:
> Thx Tim. Your solution works.

After Steven's reply, I recommend

  dict((k,v._asdict()) for k,v in d.iteritems())

which simplifies matters.

-tkc


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Re: Convert namedtuple to dictionary

[Ned Batchelder]

On 9/26/13 1:17 PM, Virendra Tripathi wrote:

Hi Ned,

Thanks. Wouldn't I have to first create a function to pull out the 'dictdict' 
from the data? I assume 'dictdict' refers to the 'brucelee' named tuple in the 
example. That's where I was getting stuck-trying to pull out the named tuples 
from the dict and operate on it.

I assumed you already had the data you showed.  This is tupledict:

{'a': brucelee(x=123, y=321), 'b': brucelee('x'=123, 'y'=321)

Given that, you create dictdict with the line I showed:

dictdict = { k: nt._asdict() for k, nt in tupledict }


Thanks,

Virendra


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Re: Download all youtube favorites with youtube-dl script

[Bill]

Joel Goldstick wrote:




On Thu, Sep 26, 2013 at 11:13 AM, Bill mailto:b...@bill.com>> wrote:

I have been using the script youtube-dl
http://rg3.github.io/youtube-__dl/ 

And I was wondering if there is a way to download all of a user's
favorites or uploads.

The script has a functionality to download all videos in a txt file.
So if there is a way using the youtube API or JSON (none of which I
am familiar with) to bring up a list of all these videos then it'd
be a simple case putting these urls into a file.

The problem is youtube displays favorites or user uploads in pages
or infinite scroll. So it is difficult to access them by the
BeautifulSoup module.


What do you suggest?
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Have you looked at the youtube API?  That would be better than screen
scraping. https://developers.google.com/youtube/getting_started


--
Joel Goldstick
http://joelgoldstick.com


I remember looking at this a while ago. These are the relevant sections 
of the API:


https://developers.google.com/youtube/2.0/developers_guide_protocol?hl=en#User_Uploaded_Videos

https://developers.google.com/youtube/2.0/developers_guide_protocol?hl=en#Favorite_Videos

The problem with the API is that with both of these, it only brings up 
25 videos e.g. https://gdata.youtube.com/feeds/api/users/scooby1961/uploads


Unless I'm missing something? There must be a way to bring up all of 
them on one page right? Or at least cycle through the rest of them.


Same problem with favorties: 
https://gdata.youtube.com/feeds/api/users/adambuxton/favorites/

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Re: Download all youtube favorites with youtube-dl script

[MRAB]

On 26/09/2013 19:14, Bill wrote:

Joel Goldstick wrote:




On Thu, Sep 26, 2013 at 11:13 AM, Bill mailto:b...@bill.com>> wrote:

I have been using the script youtube-dl
http://rg3.github.io/youtube-__dl/ 

And I was wondering if there is a way to download all of a user's
favorites or uploads.

The script has a functionality to download all videos in a txt file.
So if there is a way using the youtube API or JSON (none of which I
am familiar with) to bring up a list of all these videos then it'd
be a simple case putting these urls into a file.

The problem is youtube displays favorites or user uploads in pages
or infinite scroll. So it is difficult to access them by the
BeautifulSoup module.


What do you suggest?
--
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Have you looked at the youtube API?  That would be better than screen
scraping. https://developers.google.com/youtube/getting_started


--
Joel Goldstick
http://joelgoldstick.com


I remember looking at this a while ago. These are the relevant sections
of the API:

https://developers.google.com/youtube/2.0/developers_guide_protocol?hl=en#User_Uploaded_Videos

https://developers.google.com/youtube/2.0/developers_guide_protocol?hl=en#Favorite_Videos

The problem with the API is that with both of these, it only brings up
25 videos e.g. https://gdata.youtube.com/feeds/api/users/scooby1961/uploads

Unless I'm missing something? There must be a way to bring up all of
them on one page right? Or at least cycle through the rest of them.


You _are_ missing something. That section of "#User_Uploaded_Videos"
mentions the parameters "start-index" and "max-results".


Same problem with favorties:
https://gdata.youtube.com/feeds/api/users/adambuxton/favorites/



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Re: Newline interpretation issue with MIMEApplication with binary data, Python 3.3.2

[Piet van Oostrum]

Nils Bunger  writes:

> Hi Neil, 
>
> Thanks for looking at this.  
>
> I'm trying to create a multipart MIME for an HTTP POST request, not an
> email. This is for a third-party API that requires a multipart POST
> with a binary file, so I don't have the option to just use a different
> encoding.
>
> Multipart HTTP is standardized in HTTP 1.0 and supports binary parts.
> Also, no one will re-interpret contents of HTTP on the wire, as binary
> is quite normal in HTTP.
>
> The issue seems to be some parts of the python MIME encoder still
> assume it's for email only, where everything would be b64 encoded.
>
> Maybe I have to roll my own to create a multipart msg with a binary
> file? I was hoping to avoid that.

The email MIME stuff is not really adapted for HTTP. I would advise to
use the Requests package (http://docs.python-requests.org/en/latest/) or
the Uploading Files part from Doug Hellmann's page
(http://doughellmann.com/2009/07/pymotw-urllib2-library-for-opening-urls.html).
This is for Python2; I can send you a Python3 version if you want.
-- 
Piet van Oostrum 
WWW: http://pietvanoostrum.com/
PGP key: [8DAE142BE17999C4]
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Re: Convert namedtuple to dictionary

[Ned Batchelder]

On 9/26/13 1:42 PM, Ned Batchelder wrote:

On 9/26/13 1:17 PM, Virendra Tripathi wrote:

Hi Ned,

Thanks. Wouldn't I have to first create a function to pull out the 
'dictdict' from the data? I assume 'dictdict' refers to the 
'brucelee' named tuple in the example. That's where I was getting 
stuck-trying to pull out the named tuples from the dict and operate 
on it.

I assumed you already had the data you showed.  This is tupledict:

{'a': brucelee(x=123, y=321), 'b': brucelee('x'=123, 'y'=321)

Given that, you create dictdict with the line I showed:

dictdict = { k: nt._asdict() for k, nt in tupledict }



Oops:

dictdict = { k: nt._asdict() for k, nt in tupledict.iteritems() }

(sorry!)

--Ned.

Thanks,

Virendra




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Re: Convert namedtuple to dictionary

[Virendra Tripathi]

Thanks guys! BTW, please ignore the follow-up question there. I had written a 
script earlier which had a dict like:

{'a':[x=10, y=23,..], 'b': [x=10, y=23,…],…..}

I was thinking about that and therefore the error. Apologies.
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work develope matrix of difusive concentration

[D.YAN ESCOLAR RAMBAL]

Good morning all

thanks for your help. Now I`ve a question, if I need create a matrix,
method of thomas, ghost nodes, etc.. for developed one aplicative for the
ecuation of difusion in 1d, 2d, 3d, 4d. It`s better use phyton 3.3 or 2.7?,
if the answer is phyton 3.3 that interpreter is similar to aptana o better,
for start, and which, libraries are necesary for this,  I think I need
numpy, numba, math, mathexpretion, matiplot, but  I don`t know which is the
library similar to matlab.

All best for you, nice day or nigth and nice week
-- 

*Gracias, cordialmente, *

*
*

*
*

*ING. YANETH ESCOLAR RAMBAL*

*HAFI Engineering & Consulting GmbH*

*CEL: + 57 3166257245*

*TEL: + 57 (1) 6508308*

*TEL: ++43 5522 77924 0*

*Fax: ++43 5522 74938*

*Dir : Cll 72f no. 113-21 Torre 5 - 604  Bogotá Colombia*

*   Muehletorplatz 4-6, A-6800 Feldkirch, Austria*

   *www.hafi.cc/en/environ_en.htm*
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Re: Handling 3 operands in an expression without raising an exception

[Denis McMahon]

On Thu, 26 Sep 2013 19:58:02 +0300, Νίκος wrote:

> except socket.gaierror as e:
>   city = host = "UnKnown Origin"
> 
> But then what if in case of an error i needed different string set to be
> assigned on city and host respectively?

Oh FFS

Are you serious when you ask this?

Simply change:

except socket.gaierror as e:
city = host = "UnKnown Origin"

To:

except socket.gaierror as e:
city = "Unknown City"
host = "Unknown Host"

-- 
Denis McMahon, denismfmcma...@gmail.com
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Re: Handling 3 operands in an expression without raising an exception

[Dave Angel]

On 26/9/2013 12:58, Νίκος wrote:

   

> But actually i have 2 variables that relay on a proper ip address.
>
> ipval = ( os.environ.get('HTTP_CF_CONNECTING_IP') or 
> os.environ.get('REMOTE_ADDR', "UnKnown Origin") )
> try:
>   gi = pygeoip.GeoIP('/usr/local/share/GeoIPCity.dat')
>   city = gi.time_zone_by_addr( ipval )
>   host = socket.gethostbyaddr( ipval ) [0]
> except socket.gaierror as e:
>   city = host = "UnKnown Origin"

First concept:  A try/except should wrap one conceptual calculation.  In
this case, you have three.  So if the host lookup fails, you'll
overwrite the city you already presumably figured out.

You also don't do anything about an exception that might occur
calculating gi.  If one isn't possible, or if it's unrelated to the
other two, then that line should come OUT of the try-block.

What is city?  The function name implies it's a time zone, which is
presumably a float, -12 < x < +12.  If this is the case, then a string
is a lousy default value.

>
> But then what if in case of an error i needed different string set to be 
> assigned on city and host respectively?

Nothing limits the except clause to a single line.

>
> As i ahve it know in case of n address related error i get the smae 
> sting for both of them.
>
No idea what this is trying to say.

-- 
DaveA


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Re: Handling 3 operands in an expression without raising an exception

[Νίκος]

Στις 26/9/2013 11:16 μμ, ο/η Denis McMahon έγραψε:

On Thu, 26 Sep 2013 19:58:02 +0300, Νίκος wrote:


except socket.gaierror as e:
city = host = "UnKnown Origin"

But then what if in case of an error i needed different string set to be
assigned on city and host respectively?


Oh FFS

Are you serious when you ask this?

Simply change:

except socket.gaierror as e:
 city = host = "UnKnown Origin"

To:

except socket.gaierror as e:
 city = "Unknown City"
 host = "Unknown Host"


Yes indeed that was an idiotic question made by me, but i was somehow 
feeling again that i should handle it in one-liner, avoid wanting to use 
2 statements.


I wonder if there is a way to assign the string "Unknown Origin" to the 
variable that failed in the try block to get a value.


Can i describe that somehow inside the except block?

I mean like:

except socket.gaierror as e:
what_ever_var_failed = "Unknown Origin"
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Re: Handling 3 operands in an expression without raising an exception

[Dave Angel]

On 26/9/2013 18:14, Νίκος wrote:

> Στις 26/9/2013 11:16 μμ, ο/η Denis McMahon έγραψε:
>> On Thu, 26 Sep 2013 19:58:02 +0300, Νίκος wrote:
>>
>>> except socket.gaierror as e:
>>> city = host = "UnKnown Origin"
>>>
>>> But then what if in case of an error i needed different string set to be
>>> assigned on city and host respectively?
>>
>> Oh FFS
>>
>> Are you serious when you ask this?
>>
>> Simply change:
>>
>> except socket.gaierror as e:
>>  city = host = "UnKnown Origin"
>>
>> To:
>>
>> except socket.gaierror as e:
>>  city = "Unknown City"
>>  host = "Unknown Host"
>
> Yes indeed that was an idiotic question made by me, but i was somehow 
> feeling again that i should handle it in one-liner, avoid wanting to use 
> 2 statements.

newlines are still cheap.  And they can really help readability.

> I wonder if there is a way to assign the string "Unknown Origin" to the 
> variable that failed in the try block to get a value.
>
> Can i describe that somehow inside the except block?
>
> I mean like:
>
> except socket.gaierror as e:
>   what_ever_var_failed = "Unknown Origin"

Simply assign the default values BEFORE the try block, and use pass as
the except block.

That still doesn't get around the inadvisability of putting those 3
lines in the try block.

You still haven't dealt with the gt assignment and its possible
exception.

-- 
DaveA


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Re: Referrer key missing form os.environ dictionary?

[Grant Edwards]

On 2013-09-26, Chris Angelico  wrote:
> On Fri, Sep 27, 2013 at 12:11 AM, Grant Edwards  
> wrote:
>> On a Unix system when you invoke a program, you "pass" it four things:
>>
>>  1) A dictionary where keys/values are both strings [enviornment variables]
>>  2) A list of strings [command line args]
>>  3) A set of open file descriptors.
>>  4) The current working directory.
>>
>> You can provide input values to the program through any of these.
>>
>> For interactive programs, 2 and 3 are the most convenient.
>
> Hrm, not sure about #3 for interactive programs, unless you
> specifically mean the three standard streams.

Yes, that's what I mean: shell redirection/pipelines.  Hooking stuff
to stdin is pretty much the only example of this you'll ever see in
the wild for input data:

 foo < inputdata
 
 bar | foo
 
 foo < With most Unix shells, you should be able to set environment
> variables:
>
> PGUSER=fred PGPASSWORD=secret psql

Yep, that's rather rarely used.  The syntax/sematics for values passed
that way is very limited compared to the syntax/semantics that can be
used for command line arguments, so the latter is much more versatile.

> Not as convenient as #2, but far easier than passing an open file
> descriptor. Of course, passing file descriptors around is pretty easy
> programmatically, but when you say "interactive" I assume you're
> talking also about an interactive shell.

I probably should have said "stdin", but in theory you can pass data
in via multiple file descriptors.  Nobody does that except people
cooking up obscure examples for advanced shell scripting guides...
 
> GUI interactions of course follow their own rules completely. In most
> systems, it's really easy to invoke an application with one argument,
> a file name; it's generally much harder to customize the arguments at
> the keyboard. OS/2 had a facility for doing that. You just put square
> brackets into the configured args and it'd turn it into a prompt:
>
> --foo=bar --mode=[Choose mode, 1-3:] %*
>
> You'd get a nice little popup with the prompt you specified, and
> whatever you type gets put into the args. Haven't seen that in any
> other system - at least, not as conveniently.

-- 
Grant Edwards   grant.b.edwardsYow! I request a weekend in
  at   Havana with Phil Silvers!
  gmail.com
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Re: Handling 3 operands in an expression without raising an exception

[alex23]

On 26/09/2013 6:39 PM, Νίκος wrote:

You dont have to be ironic. I dont have the experience you do.


This is bulshytt. You only just a few days ago started a thread in which 
handling lookups in dictionaries with potentially non-existent keys was 
dealt with. At length. And now you're restructuring pretty much the 
exact same question to troll the list. Again.


You're either not reading what people are saying, not trying to 
understand things by working with simpler examples at the interpreter, 
or just flat out lying. In any case, you're not acting in good faith.

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Re: work develope matrix of difusive concentration

[rusi]

On Friday, September 27, 2013 12:43:51 AM UTC+5:30, D.YAN ESCOLAR RAMBAL wrote:
> Good morning all
> 
> thanks for your help. Now I`ve a question, if I need create a matrix, method 
> of thomas, ghost nodes, etc.. for developed one aplicative for the ecuation 
> of difusion in 1d, 2d, 3d, 4d. It`s better use phyton 3.3 or 2.7?, if the 
> answer is phyton 3.3 that interpreter is similar to aptana o better, for 
> start, and which, libraries are necesary for this,  I think I need numpy, 
> numba, math, mathexpretion, matiplot, but  I don`t know which is the library 
> similar to matlab.

Sage??
http://en.wikipedia.org/wiki/Sage_%28mathematics_software%29

[I dont know this area myself]
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Re: Nosetests

[melwin9]

Initially I was shown pexpect, leaving that there, Can i make up 5 tests? I 
tried tests two different ways and no luck. What am I supposed to be writing up 
when I do a test and is there a particular way I can/should be referencing it 
back to its main file?

THis is what I have for the test_guess.py

from unittest import TestCase
import pexpect as pe

import guess as g
import random

random_number = random.randrange(1, 10)
correct = False

class GuessTest(TestCase):
def setUp(self):
self.intro = 'I have chosen a number from 1-10'
self.request = 'Guess a number: '
self.responseHigh = "That's too high."
self.responseLow  = "That's too low."
self.responseCorrect = "That's right!"
self.goodbye = 'Goodbye and thanks for playing!'

def test_main(self):
#cannot execute main now because it will
#require user input
from guess import main

def test_guessing_hi_low_4(self):
# Conversation assuming number is 4
child = pe.spawn('python guess.py')
child.expect(self.intro,timeout=5)
child.expect(self.request,timeout=5)
child.sendline('5')
child.expect(self.responseHigh,timeout=5)
child.sendline('3')
child.expect(self.responseLow,timeout=5)
child.sendline('4')
child.expect(self.responseCorrect,timeout=5)
child.expect(self.goodbye,timeout=5)


def __init__(self):
self.number = random.randint(0,10)
HIGH = 1
LOW = 2
OK = 3

def guess(self, number):
if number > self.number:
 return self.HIGH
if number < self.number:
 return self.LOW
return self.OK

def test_guesstoolow(self):
while not correct:
guess = input("What could it be?")
if guess == random_number:
print "Congrats You Got It"
correct = True
elif guess > random_number:
print "To High"
elif guess < random_number:
print "To Low"
else:
print "Try Again"


and the guess.py file is


intro = 'I have chosen a number from 1-10'
request = 'Guess a number: '
responseHigh = "That's too high."
responseLow  = "That's too low."
responseCorrect = "That's right!"
goodbye = 'Goodbye and thanks for playing!'

def main():
print(intro)
user_input = raw_input(request)
print(responseHigh)
print(request)
user_input = raw_input(request)
print(responseLow)
user_input = raw_input(request)
print(responseCorrect)
print(goodbye)

if __name__ == '__main__':
main()


On Wednesday, September 25, 2013 11:48:59 PM UTC-4, Roy Smith wrote:
> In article 
> 
>   wrote:
> 
> 
> 
> > Not sure How to proceed on with writing a few more tests with if statement 
> > to 
> 
> > test if the value is low or high. I was told to try a command line switch 
> 
> > like optparse to pass the number but not sure how to do that either. 
> 
> 
> 
> One thing I would recommend is refactoring your game to keep the game 
> 
> logic distinct from the I/O.
> 
> 
> 
> If I was designing this, I would have some sort of game engine class, 
> 
> which stores all the state for a game.  I imagine the first thing you 
> 
> need to do is pick a random number and remember it.  Then, you'll need a 
> 
> function to take a guess and tell you if it's too high, too low, or 
> 
> correct.  Something like:
> 
> 
> 
> class NumberGuessingGame:
> 
>def __init__(self):
> 
>   self.number = random.randint(0, 10)
> 
> 
> 
>HIGH = 1
> 
>LOW = 2
> 
>OK = 3
> 
> 
> 
>def guess(self, number):
> 
>   if number > self.number:
> 
>  return self.HIGH
> 
>   if number < self.number:
> 
>  return self.LOW
> 
>   return self.OK
> 
> 
> 
> Now you've got something that's easy to test without all this pexpect 
> 
> crud getting in the way.  Then, your game application can create an 
> 
> instance of NumberGuessingGame and wrap the required I/O operations 
> 
> around that.
> 
> 
> 
> I'd also probably add some way to bypass the random number generator and 
> 
> set the number you're trying to guess directly.  This will make it a lot 
> 
> easier to test edge cases.

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Re: Nosetests

[Roy Smith]

In article ,
 melw...@gmail.com wrote:

> Initially I was shown pexpect, leaving that there, Can i make up 5 tests? I 
> tried tests two different ways and no luck. What am I supposed to be writing 
> up when I do a test and is there a particular way I can/should be referencing 
> it back to its main file?

I'm not sure I understand your question.  Are you asking:

Q1: "What tests should I be writing?"

or

Q2: "Once I know what I want to test, how do I implement those tests?"

I'm guessing Q1, so that's what I'm going to base the rest of this post 
on.  Before you cat write a test, you have to understand what your code 
is supposed to do.  So, for example, let's say the specification for 
your program runs something like this:

When you run the program, it will print, "I have chosen a number from 
1-10", and then it will print, "Guess a number: ".  It will then wait 
for input.  When you type an integer, it will print either, "That's too 
high.", "That's too low.", or "That's right!".

Now, let's look at one of your tests:

def test_guessing_hi_low_4(self):

# Conversation assuming number is 4
child = pe.spawn('python guess.py')
child.expect(self.intro,timeout=5)
child.expect(self.request,timeout=5)
child.sendline('5')
child.expect(self.responseHigh,timeout=5)
child.sendline('3')
child.expect(self.responseLow,timeout=5)
child.sendline('4')
child.expect(self.responseCorrect,timeout=5)
child.expect(self.goodbye,timeout=5)

It looks pretty reasonable up to the point where you do:

child.sendline('5')
child.expect(self.responseHigh,timeout=5)

The problem is, you don't know what number it picked, so you can't 
predict what response it will have to an input of 5.  This goes back to 
what I was saying earlier.  You need some way to set the game to a known 
state, so you can test its responses, in that state, to various inputs.

If you're going to stick with the pexpect interface, then maybe you need 
a command line argument to override the random number generator and set 
the game to a specific number.  So, you can run:

$ python guess.py --test 4

and now you know the number it has picked is 4.  If you send it 5, it 
should tell you too high.  If you send it 3, it should tell you too low.  
And so on.

This is standard procedure in all kinds of testing.  You need some way 
to set the system being tested to a known state.  Then (and only then) 
can you apply various inputs and observe what outputs you get.  This is 
true of hardware was well.  Integrated circuits often have a "test 
mode", where you can set the internal state of the chip to some known 
configuration before you perform a test.
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Re: Nosetests

[melwin9]

The question was more like what tests should I be writing, fine if I remove the 
pexpect test I tried the test_guess & test_guesstoolow and still unable to get 
it to work. So if i Want to ask for a number and typed a number which is at 
random indicated by the top of the code, how do I proceed on with my tests?

On Thursday, September 26, 2013 9:16:32 PM UTC-4, Roy Smith wrote:
> In article ,
> 
>  wrote:
> 
> 
> 
> > Initially I was shown pexpect, leaving that there, Can i make up 5 tests? I 
> 
> > tried tests two different ways and no luck. What am I supposed to be 
> > writing 
> 
> > up when I do a test and is there a particular way I can/should be 
> > referencing 
> 
> > it back to its main file?
> 
> 
> 
> I'm not sure I understand your question.  Are you asking:
> 
> 
> 
> Q1: "What tests should I be writing?"
> 
> 
> 
> or
> 
> 
> 
> Q2: "Once I know what I want to test, how do I implement those tests?"
> 
> 
> 
> I'm guessing Q1, so that's what I'm going to base the rest of this post 
> 
> on.  Before you cat write a test, you have to understand what your code 
> 
> is supposed to do.  So, for example, let's say the specification for 
> 
> your program runs something like this:
> 
> 
> 
> When you run the program, it will print, "I have chosen a number from 
> 
> 1-10", and then it will print, "Guess a number: ".  It will then wait 
> 
> for input.  When you type an integer, it will print either, "That's too 
> 
> high.", "That's too low.", or "That's right!".
> 
> 
> 
> Now, let's look at one of your tests:
> 
> 
> 
> def test_guessing_hi_low_4(self):
> 
> 
> 
> # Conversation assuming number is 4
> 
> child = pe.spawn('python guess.py')
> 
> child.expect(self.intro,timeout=5)
> 
> child.expect(self.request,timeout=5)
> 
> child.sendline('5')
> 
> child.expect(self.responseHigh,timeout=5)
> 
> child.sendline('3')
> 
> child.expect(self.responseLow,timeout=5)
> 
> child.sendline('4')
> 
> child.expect(self.responseCorrect,timeout=5)
> 
> child.expect(self.goodbye,timeout=5)
> 
> 
> 
> It looks pretty reasonable up to the point where you do:
> 
> 
> 
> child.sendline('5')
> 
> child.expect(self.responseHigh,timeout=5)
> 
> 
> 
> The problem is, you don't know what number it picked, so you can't 
> 
> predict what response it will have to an input of 5.  This goes back to 
> 
> what I was saying earlier.  You need some way to set the game to a known 
> 
> state, so you can test its responses, in that state, to various inputs.
> 
> 
> 
> If you're going to stick with the pexpect interface, then maybe you need 
> 
> a command line argument to override the random number generator and set 
> 
> the game to a specific number.  So, you can run:
> 
> 
> 
> $ python guess.py --test 4
> 
> 
> 
> and now you know the number it has picked is 4.  If you send it 5, it 
> 
> should tell you too high.  If you send it 3, it should tell you too low.  
> 
> And so on.
> 
> 
> 
> This is standard procedure in all kinds of testing.  You need some way 
> 
> to set the system being tested to a known state.  Then (and only then) 
> 
> can you apply various inputs and observe what outputs you get.  This is 
> 
> true of hardware was well.  Integrated circuits often have a "test 
> 
> mode", where you can set the internal state of the chip to some known 
> 
> configuration before you perform a test.

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Re: Nosetests

[melwin9]

I modified  the guess.py file but am unable to run it, how do I go about 
writing tests for this.

import random

guessesTaken = 0

number = random.randint(1, 10)

intro = 'I have chosen a number from 1-10'
request = 'Guess a number: '
responseHigh = "That's too high."
responseLow  = "That's too low."
responseCorrect = "That's right!"
goodbye = 'Goodbye and thanks for playing!'

print(intro)
def main():
while guessesTaken < 5:
print(request)
guess = input()
guess = int(guess)

guessesTaken = guessesTaken + 1

if guess < number:
print(responseLow) 

if guess > number:
print(responseHigh)

if guess == number:
break

if guess == number:
guessesTaken = str(guessesTaken)
print(responseCorrect + '! You guessed my number in ' + 
guessesTaken + ' guesses!')

if guess != number:
number = str(number)
print(goodbye + ' The number I was thinking of was ' + number)

##def main():
#print(intro)
 #   user_input = raw_input(request)
  #  print(responseHigh)
  #  print(request)
  #  user_input = raw_input(request)
  #  print(responseLow)
  #  user_input = raw_input(request)
  #  print(responseCorrect)
  #  print(goodbye)

if __name__ == '__main__':
main()


On Thursday, September 26, 2013 9:37:39 PM UTC-4,  wrote:
> The question was more like what tests should I be writing, fine if I remove 
> the pexpect test I tried the test_guess & test_guesstoolow and still unable 
> to get it to work. So if i Want to ask for a number and typed a number which 
> is at random indicated by the top of the code, how do I proceed on with my 
> tests?
> 
> 
> 
> On Thursday, September 26, 2013 9:16:32 PM UTC-4, Roy Smith wrote:
> 
> > In article ,
> 
> > 
> 
> >  wrote:
> 
> > 
> 
> > 
> 
> > 
> 
> > > Initially I was shown pexpect, leaving that there, Can i make up 5 tests? 
> > > I 
> 
> > 
> 
> > > tried tests two different ways and no luck. What am I supposed to be 
> > > writing 
> 
> > 
> 
> > > up when I do a test and is there a particular way I can/should be 
> > > referencing 
> 
> > 
> 
> > > it back to its main file?
> 
> > 
> 
> > 
> 
> > 
> 
> > I'm not sure I understand your question.  Are you asking:
> 
> > 
> 
> > 
> 
> > 
> 
> > Q1: "What tests should I be writing?"
> 
> > 
> 
> > 
> 
> > 
> 
> > or
> 
> > 
> 
> > 
> 
> > 
> 
> > Q2: "Once I know what I want to test, how do I implement those tests?"
> 
> > 
> 
> > 
> 
> > 
> 
> > I'm guessing Q1, so that's what I'm going to base the rest of this post 
> 
> > 
> 
> > on.  Before you cat write a test, you have to understand what your code 
> 
> > 
> 
> > is supposed to do.  So, for example, let's say the specification for 
> 
> > 
> 
> > your program runs something like this:
> 
> > 
> 
> > 
> 
> > 
> 
> > When you run the program, it will print, "I have chosen a number from 
> 
> > 
> 
> > 1-10", and then it will print, "Guess a number: ".  It will then wait 
> 
> > 
> 
> > for input.  When you type an integer, it will print either, "That's too 
> 
> > 
> 
> > high.", "That's too low.", or "That's right!".
> 
> > 
> 
> > 
> 
> > 
> 
> > Now, let's look at one of your tests:
> 
> > 
> 
> > 
> 
> > 
> 
> > def test_guessing_hi_low_4(self):
> 
> > 
> 
> > 
> 
> > 
> 
> > # Conversation assuming number is 4
> 
> > 
> 
> > child = pe.spawn('python guess.py')
> 
> > 
> 
> > child.expect(self.intro,timeout=5)
> 
> > 
> 
> > child.expect(self.request,timeout=5)
> 
> > 
> 
> > child.sendline('5')
> 
> > 
> 
> > child.expect(self.responseHigh,timeout=5)
> 
> > 
> 
> > child.sendline('3')
> 
> > 
> 
> > child.expect(self.responseLow,timeout=5)
> 
> > 
> 
> > child.sendline('4')
> 
> > 
> 
> > child.expect(self.responseCorrect,timeout=5)
> 
> > 
> 
> > child.expect(self.goodbye,timeout=5)
> 
> > 
> 
> > 
> 
> > 
> 
> > It looks pretty reasonable up to the point where you do:
> 
> > 
> 
> > 
> 
> > 
> 
> > child.sendline('5')
> 
> > 
> 
> > child.expect(self.responseHigh,timeout=5)
> 
> > 
> 
> > 
> 
> > 
> 
> > The problem is, you don't know what number it picked, so you can't 
> 
> > 
> 
> > predict what response it will have to an input of 5.  This goes back to 
> 
> > 
> 
> > what I was saying earlier.  You need some way to set the game to a known 
> 
> > 
> 
> > state, so you can test its responses, in that state, to various inputs.
> 
> > 
> 
> > 
> 
> > 
> 
> > If you're going to stick with the pexpect interface, then maybe you need 
> 
> > 
> 
> > a command line argument to override the random number generator and set 
> 
> > 
> 
> > the game to a specific number.  So, you can run:
> 
> > 
> 
> > 
> 
> > 
> 
> > $ python guess.py --test 4
> 
> > 
> 
> > 
> 
> > 
> 
> > and now you know the number it has picked is 4.  If you send it 5, it 
> 
> > 
> 
> > should tell you too high.  If you send it 3, it should tell you too low. 

Re: Nosetests

[Steven D'Aprano]

On Thu, 26 Sep 2013 21:20:52 -0700, melwin9 wrote:

> I modified  the guess.py file but am unable to run it, 

What does that mean?

How do you try to run it?

What happens when you do?



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Steven
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Re: Referrer key missing form os.environ dictionary?

[Chris Angelico]

On Fri, Sep 27, 2013 at 9:27 AM, Grant Edwards  wrote:
> I probably should have said "stdin", but in theory you can pass data
> in via multiple file descriptors.  Nobody does that except people
> cooking up obscure examples for advanced shell scripting guides...

Yep. With that variant, I agree that it's more common than env vars
(apart from standard ones - *heaps* of programs are affected by stuff
like LANG or HOME or PATH, but they're not passed at the command
line); what your description put me in mind of, though, was the
special handling sometimes done between two programs, like when the
Unix program loader finds a #! and exec's an interpreter to process
the script - for security, it has to pass the fd, not the file name,
to the interpreter. But that's really esoteric!

Of course, whenever you fork without execing (execking?), you can pass
(or share) file descriptors easily. Very common, but not exactly
command-line stuff.

ChrisA
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