Re: Message passing syntax for objects
On 2013-03-18, Mark Janssen wrote: > Alan Kay's idea of message-passing in Smalltalk are interesting, and > like the questioner says, never took off. My answer was that Alan > Kay's abstraction of "Everything is an object" fails because you can't > have message-passing, an I/O task, working in the same space as your > objects -- they are two very different functionalities and they have > to be preserved **for the programmer**. Without concurrency, message passing and interacting through functions are semantically similar. You have operating for sending and receiving messages. Python does this through methods which potentially have inputs and outputs. Function syntax does have two slight advantages over pure message passing. 1. A command is sent with the message as opposed to requiring requests to be parsed from the message separately from the data. 2. Functions constrain what actions are available and what inputs they can legal accept. This is doubly true With concurrency, CSP has shown us that message passing is valuable for syncronization. Most CSP languages retain the idea of passing messages. This need not be the case. The same semantics could be acheived through function call syntax, although it would likely be less intuitive. If you want to pursue your ideas further, and you have not already, I suggest that you investigate Erlang and its CSP based "concurrent oriented programming." Alan Kay, himself, commented that he felt it matched his ideas of message based OOP. When you return, there is a "Candygram" package providing similar constructs (last I knew, it did not yet impliment light weight processes) for Python. You might also look at using Go which has CSP based channel and coroutine semantics. It has many things in common with Python. -- http://mail.python.org/mailman/listinfo/python-list
Just curious - I thought dict keys would maintain sequence
Hi all I know that you cannot rely on the order of keys in a dictionary, and I am not attempting to do so. Nevertheless, the following surprised me. A program creates a dictionary with a known set of keys. I would have thought that multiple runs of the program would return the keys in the same sequence. As you can see, the results appear to be totally random. Just out of interest, I would appreciate an explanation. Thanks Frank Millman F:\>type test.py test_list = [ 'ert', 'jhg', 'yer', 'nli', 'vrg', 'qnh', 'kyh', 'cgj', 'lys', 'vyk', 'dws', 'fuj', 'ghj', 'puy', 'brc', 'dhy', 'jkl', 'gfd', 'jtf', 'dfp'] test_dict = dict([(x, None) for x in test_list]) print(test_dict.keys()) F:\>test.py dict_keys(['ghj', 'qnh', 'lys', 'ert', 'jhg', 'dfp', 'vrg', 'dws', 'jtf', 'puy', 'yer', 'brc', 'kyh', 'jkl', 'gfd', 'nli', 'fuj', 'dhy', 'cgj', 'vyk']) F:\>test.py dict_keys(['vrg', 'dfp', 'brc', 'yer', 'nli', 'jhg', 'cgj', 'ert', 'dws', 'gfd', 'puy', 'vyk', 'ghj', 'jkl', 'jtf', 'kyh', 'qnh', 'fuj', 'dhy', 'lys']) F:\>test.py dict_keys(['yer', 'nli', 'brc', 'fuj', 'cgj', 'dfp', 'dhy', 'vrg', 'jkl', 'jtf', 'vyk', 'ghj', 'qnh', 'kyh', 'gfd', 'ert', 'dws', 'jhg', 'lys', 'puy']) Python version is 3.3.0, win32. -- http://mail.python.org/mailman/listinfo/python-list
Re: Just curious - I thought dict keys would maintain sequence
On Mon, Mar 18, 2013 at 6:26 PM, Frank Millman wrote: > Hi all > > I know that you cannot rely on the order of keys in a dictionary, and I am > not attempting to do so. > > Nevertheless, the following surprised me. A program creates a dictionary > with a known set of keys. I would have thought that multiple runs of the > program would return the keys in the same sequence. As you can see, the > results appear to be totally random. > > Just out of interest, I would appreciate an explanation. Mainly, it's just something you utterly cannot depend on, so it's allowed to vary based on the phase of the moon, the position of your hard drive platters, or anything else it likes. The hashing is actually randomized in recent versions of Python as a defense against a denial of service attack by generating hash collisions; that's most likely what you're seeing there. The dictionary object is not deterministic to that extent. :) ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: How to add the current dir to sys.path when calling a python file?
On Mar 18, 8:56 am, Peng Yu wrote: > Hi, > > man python says "If a script argument is given, the directory > containing the script is inserted in the path in front of $PYTHONPATH. > The search path can be manipulated from within a Python program as > the variable sys.path." Instead I want to have the current directory > inserted to the front of $PYTHONPATH without changing anything the > script. Is there a way to do so? > > -- > Regards, > Peng Have you seen http://docs.python.org/2/library/site.html ? -- http://mail.python.org/mailman/listinfo/python-list
Re: Just curious - I thought dict keys would maintain sequence
On 18/03/2013 09:31, Chris Angelico wrote: On Mon, Mar 18, 2013 at 6:26 PM, Frank Millman wrote: Hi all I know that you cannot rely on the order of keys in a dictionary, and I am not attempting to do so. Nevertheless, the following surprised me. A program creates a dictionary with a known set of keys. I would have thought that multiple runs of the program would return the keys in the same sequence. As you can see, the results appear to be totally random. Just out of interest, I would appreciate an explanation. Mainly, it's just something you utterly cannot depend on, so it's allowed to vary based on the phase of the moon, the position of your hard drive platters, or anything else it likes. The hashing is actually randomized in recent versions of Python as a defense against a denial of service attack by generating hash collisions; that's most likely what you're seeing there. The dictionary object is not deterministic to that extent. :) Now that you mention it, I do remember reading about the recent addition of a random element to the hashing mechanism. I am sure that is the explanation. Thanks, Chris Frank -- http://mail.python.org/mailman/listinfo/python-list
Re: Just curious - I thought dict keys would maintain sequence
Chris Angelico wrote:
> On Mon, Mar 18, 2013 at 6:26 PM, Frank Millman wrote:
>> Hi all
>>
>> I know that you cannot rely on the order of keys in a dictionary, and I
>> am not attempting to do so.
>>
>> Nevertheless, the following surprised me. A program creates a dictionary
>> with a known set of keys. I would have thought that multiple runs of the
>> program would return the keys in the same sequence. As you can see, the
>> results appear to be totally random.
>>
>> Just out of interest, I would appreciate an explanation.
>
> Mainly, it's just something you utterly cannot depend on, so it's
> allowed to vary based on the phase of the moon, the position of your
> hard drive platters, or anything else it likes. The hashing is
> actually randomized in recent versions of Python as a defense against
> a denial of service attack by generating hash collisions; that's most
> likely what you're seeing there. The dictionary object is not
> deterministic to that extent. :)
If you set the PYTHONHASHSEED environment variable you will see the same
order for every invocation. Anecdotal evidence:
$ python3.3 -c'print(dict.fromkeys("abcde", ""))'
{'c': '', 'b': '', 'a': '', 'e': '', 'd': ''}
$ python3.3 -c'print(dict.fromkeys("abcde", ""))'
{'a': '', 'c': '', 'b': '', 'e': '', 'd': ''}
$ python3.3 -c'print(dict.fromkeys("abcde", ""))'
{'b': '', 'c': '', 'a': '', 'd': '', 'e': ''}
$ PYTHONHASHSEED=42 python3.3 -c'print(dict.fromkeys("abcde", ""))'
{'e': '', 'd': '', 'a': '', 'c': '', 'b': ''}
$ PYTHONHASHSEED=42 python3.3 -c'print(dict.fromkeys("abcde", ""))'
{'e': '', 'd': '', 'a': '', 'c': '', 'b': ''}
$ PYTHONHASHSEED=42 python3.3 -c'print(dict.fromkeys("abcde", ""))'
{'e': '', 'd': '', 'a': '', 'c': '', 'b': ''}
Only str, byte and datetime keys are affected. See
http://docs.python.org/dev/reference/datamodel.html#object.__hash__
http://docs.python.org/dev/using/cmdline.html#envvar-PYTHONHASHSEED
--
http://mail.python.org/mailman/listinfo/python-list
Re: Just curious - I thought dict keys would maintain sequence
On Mon, 18 Mar 2013 18:31:33 +1100, Chris Angelico wrote: > On Mon, Mar 18, 2013 at 6:26 PM, Frank Millman > wrote: >> Hi all >> >> I know that you cannot rely on the order of keys in a dictionary, and I >> am not attempting to do so. >> >> Nevertheless, the following surprised me. A program creates a >> dictionary with a known set of keys. I would have thought that multiple >> runs of the program would return the keys in the same sequence. As you >> can see, the results appear to be totally random. >> >> Just out of interest, I would appreciate an explanation. > > Mainly, it's just something you utterly cannot depend on, so it's > allowed to vary based on the phase of the moon, the position of your > hard drive platters, or anything else it likes. The hashing is actually > randomized in recent versions of Python as a defense against a denial of > service attack by generating hash collisions; that's most likely what > you're seeing there. The dictionary object is not deterministic to that > extent. :) Correct. If you try the same in Python 3.2 instead of 3.3, you will get the same order each time. You can read more about the dictionary hashing attack here: http://mail.python.org/pipermail/python-dev/2011-December/115116.html http://bugs.python.org/issue13703 http://bugs.python.org/issue14621 The current status is that Python's dict hashes are improved, but still leak enough information that attackers can cause a Denial Of Service attack with just a bit more effort than before, but work is ongoing to solve this issue. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
So, by introducing this collaboration mechanism with a syntax that defines it as sending and receiving things that are *not* arbitrary objects, the language would naturally reinforce a more thoroughly decoupled architecture? Sent from my iPad On Mar 17, 2013, at 8:53 PM, Mark Janssen wrote: > Hello, > > I just posted an answers on quora.com about OOP (http://qr.ae/TM1Vb) > and wanted to engage the python community on the subject. > > Alan Kay's idea of message-passing in Smalltalk are interesting, and > like the questioner says, never took off. My answer was that Alan > Kay's abstraction of "Everything is an object" fails because you can't > have message-passing, an I/O task, working in the same space as your > objects -- they are two very different functionalities and they have > to be preserved **for the programmer**. > > This functional separation made me think that Python could benefit > from a syntactical, language-given separation between Classes and the > messages between them, to encourage loosely-coupled, modular OOP. > Something that OOP has always promised but never delivered. > > I think we should co-opt C++'s poorly used >> and << I/O operators > (for files) and re-purpose them for objects/classes. One could then > have within interpreter space, the ability to pass in a message to an > object. > 42 >> MyObject #sends 42 as a message into MyObject > > The Object definition would then have special methods __in__ to > receive data and a special way of outputing data that can be caught > __str__(?). > > I'm hoping the community can comment on the matter > > Thanks, > > Mark > Tacoma, Washington > ___ > Python-ideas mailing list > python-id...@python.org > http://mail.python.org/mailman/listinfo/python-ideas -- http://mail.python.org/mailman/listinfo/python-list
Read utf-8 file
File have China Made
中國 製
http://www.fileformat.info/info/unicode/char/4e2d/index.htm
UTF-16 (hex)0x4E2D (4e2d)
UTF-8 (hex) 0xE4 0xB8 0xAD (e4b8ad)
Read by od -cx utf_a.text
000 中 ** ** 國 ** ** 製 ** ** \n
e4b8ade59c8be8a3bd0a
012
Read by python, why python display as beow ?
中國製
u'\u4e2d\u570b\u88fd\n' <--- Value 中國製
<-- UTF-8 value
u'\u4e2d' 中 CJK UNIFIED IDEOGRAPH-4E2D
u'\u570b' 國 CJK UNIFIED IDEOGRAPH-570B
u'\u88fd' 製 CJK UNIFIED IDEOGRAPH-88FD
import unicodedata
import codecs # UNICODE
file = codecs.open(options.filename, 'r','utf-8' )
try:
for line in file:
#print repr(line)
#print "="
print line.encode("utf")
for keys in line.split(","):
print repr(keys) ," <--- Value" , keys.encode("utf") ,"<--
UTF-8 value"
for key in keys:
try:
name = unicodedata.name(unicode(key))
print "%-9s %-8s %-30s" % ( (repr(key)),
key.encode("utf") , name )
How to display
e4b8ad for 中 in python ?
--
http://mail.python.org/mailman/listinfo/python-list
Re: Read utf-8 file
moonhkt wrote:
> How to display
> e4b8ad for 中 in python ?
Python 2
>>> print u"中".encode("utf-8").encode("hex")
e4b8ad
Python 3
>>> print(binascii.b2a_hex("中".encode("utf-8")).decode("ascii"))
e4b8ad
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to add the current dir to sys.path when calling a python file?
On 03/17/2013 11:56 PM, Peng Yu wrote: Hi, man python says "If a script argument is given, the directory containing the script is inserted in the path in front of $PYTHONPATH. The search path can be manipulated from within a Python program as the variable sys.path." Instead I want to have the current directory inserted to the front of $PYTHONPATH without changing anything the script. Is there a way to do so? if the script you're running is in the current directory, it'll just already do what you seem to be asking. cd /home/davea/temppython cat peng.;py import sys print "sys.path is", sys.path python peng.py sys.path is ['/home/davea/temppython', '/usr/lib/python2.7', '/usr/lib/python2.7/plat-linux2', '/usr/lib/python2.7/lib-tk', '/usr/lib/python2.7/lib-old', '/usr/l . The text you quoted is trying to say that there are 3 different ways you can modify the search path. The script name's location, the $PYTHONPATH environment variable, and the sys.path Python variable. -- DaveA -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python 2.7.3] What's the difference between these two uses of "for"?
On 03/17/2013 10:14 PM, Yves S. Garret wrote: I don't get why it's posting what I said twice... Because you're using googlegroups, and haven't unchecked some poorly defined default setting. You're posting both to python-list and to comp.lang.python, each of which is mirrored to the other. That's one of at least two problems with posting via googlegroups. The other is the stupid double-spacing of quotes, which is very annoying to others. See: http://wiki.python.org/moin/GoogleGroupsPython -- DaveA -- http://mail.python.org/mailman/listinfo/python-list
"Learn Python Quickly" is FREE today March 18th
For just today, the book "Learn Python Quickly" is free to download from Amazon. Also, go to www.learnpythonquickly.com for more information. -- http://mail.python.org/mailman/listinfo/python-list
"eval vs operator.methodcaller" - which is better?
Hi,
I have a program that picks module and method name from a
configuration file and executes the method. I have found two ways to
achieve this.
Apporach 1:
---
moduleName = 'mymodule'#These two variables are read from conf file.
methodName = 'mymethod'
import operator
myModule = __import__('mymodule')
myMethod = operator.methodcaller('mymethod')
val = myMethod(myModule)
print val
---
Apporach 2:
---
moduleName = 'mymodule'#These two variables are read from conf file.
methodName = 'mymethod'
val = eval('myModule.' + methodName + '()')
print val
---
Question: Which approach is better and why. Is there any other better
way to do this?
Regards,
Laxmikant
--
http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
On Tue, Mar 19, 2013 at 12:30 AM, Laxmikant Chitare
wrote:
> moduleName = 'mymodule'#These two variables are read from conf file.
> methodName = 'mymethod'
>
> import operator
> myModule = __import__('mymodule')
> myMethod = operator.methodcaller('mymethod')
> val = myMethod(myModule)
> print val
Is there any reason not to do the obvious?
val = myModule.__getattribute__(methodName)(... args ...)
Works in 2.6 and 3.3, at least on the trivial example I tried.
ChrisA
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to add the current dir to sys.path when calling a python file?
On Mon, Mar 18, 2013 at 1:54 AM, Steven D'Aprano wrote: > On Sun, 17 Mar 2013 22:56:07 -0500, Peng Yu wrote: > >> Hi, >> >> man python says "If a script argument is given, the directory >> containing the script is inserted in the path in front of $PYTHONPATH. >> The search path can be manipulated from within a Python program as the >> variable sys.path." Instead I want to have the current directory >> inserted to the front of $PYTHONPATH without changing anything the >> script. Is there a way to do so? > > No. If you want to manipulate the path, you have to write code to do so, > and put it in your script. That's very simple: > > import os, sys > sys.path.insert(0, os.getcwd()) Actually, it is quite simple. Just use stdin to take the python file. ~/linux/test/python/man/library/sys/path$ cat.sh main.py subdir/main.py ==> main.py <== #!/usr/bin/env python import sys print sys.path ==> subdir/main.py <== #!/usr/bin/env python import sys print sys.path ~/linux/test/python/man/library/sys/path$ diff <(python - < main.py) <(python - < subdir/main.py) -- Regards, Peng -- http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
Aha, that was smart Chris. Thank you.
But this raises another question in my mind. What is the use case for
operator.methodcaller ?
On 3/18/13, Chris Angelico wrote:
> On Tue, Mar 19, 2013 at 12:30 AM, Laxmikant Chitare
> wrote:
>> moduleName = 'mymodule'#These two variables are read from conf file.
>> methodName = 'mymethod'
>>
>> import operator
>> myModule = __import__('mymodule')
>> myMethod = operator.methodcaller('mymethod')
>> val = myMethod(myModule)
>> print val
>
> Is there any reason not to do the obvious?
>
> val = myModule.__getattribute__(methodName)(... args ...)
>
> Works in 2.6 and 3.3, at least on the trivial example I tried.
>
> ChrisA
> --
> http://mail.python.org/mailman/listinfo/python-list
>
--
http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
- Original Message -
> Hi,
>
> I have a program that picks module and method name from a
> configuration file and executes the method. I have found two ways to
> achieve this.
>
> Apporach 1:
> ---
> moduleName = 'mymodule'#These two variables are read from conf
> file.
> methodName = 'mymethod'
>
> import operator
> myModule = __import__('mymodule')
> myMethod = operator.methodcaller('mymethod')
> val = myMethod(myModule)
> print val
> ---
>
> Apporach 2:
> ---
> moduleName = 'mymodule'#These two variables are read from conf
> file.
> methodName = 'mymethod'
>
> val = eval('myModule.' + methodName + '()')
> print val
> ---
>
> Question: Which approach is better and why. Is there any other better
> way to do this?
>
> Regards,
> Laxmikant
> --
> http://mail.python.org/mailman/listinfo/python-list
>
Hi,
Any alternative to eval is always better than eval (aka eval is evil).
Your code is not working in my python 2.5 env (operator has no methodcaller).
try something like
moduleName = 'mymodule'#These two variables are read from conf file.
methodName = 'mymethod'
myModule = __import__(moduleName)
myFunc = getattr(myModule, methodName)
myFunc()
JM
-- IMPORTANT NOTICE:
The contents of this email and any attachments are confidential and may also be
privileged. If you are not the intended recipient, please notify the sender
immediately and do not disclose the contents to any other person, use it for
any purpose, or store or copy the information in any medium. Thank you.
--
http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
On Tue, Mar 19, 2013 at 12:58 AM, Jean-Michel Pichavant wrote: > myFunc = getattr(myModule, methodName) Doh! Thanks. I knew there was a shorter way of spelling it, rather than digging with dunder methods. That's the way I would recommend - slight tweak from the __getattribute__ version. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
On Tue, Mar 19, 2013 at 12:58 AM, Laxmikant Chitare wrote: > Aha, that was smart Chris. Thank you. > > But this raises another question in my mind. What is the use case for > operator.methodcaller ? Most of the operator module is functional versions of what can be done elsewhere with operators. They're not generally needed unless you specifically need a function, such as for a map() call: >>> a=[1,2,3,4,5] >>> b=[50,40,30,20,10] >>> list(map(operator.add,a,b)) [51, 42, 33, 24, 15] (The list() call is unnecessary in Python 2, but means this will also work in Python 3.) ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: What's the easiest Python datagrid GUI (preferably with easy database hooks as well)?
Am 17.03.2013 16:50, schrieb rusi: About your python I cant say, but your English looks/sounds as good as a native's. So dont waste your time getting that right; its good enough! Thank you. Flowers go to Dorothy L. Sayers, most of them. As far as Dabo is concerned, at the moment I just have to know how to spell "crash" ... Sibylle -- http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
Santosh Kumar writes: > This simple script is about a public transport, here is the code: > > def report_status(should_be_on, came_on): > if should_be_on < 0.0 or should_be_on > 24.0 or came_on < 0.0 or > came_on > 24.0: > return 'time not in range' > elif should_be_on == came_on: > return 'on time' > elif should_be_on > came_on: > return 'early' > elif should_be_on < came_on: > return 'delayed' > else: > return 'something might be wrong' > > print(report_status(123, 12.0)) > > I am looking forward of make the line starting with `if` short. > > Any tips are welcome. A double tip: if (not (0.0 <= should_be_on <= 24.0) or not (0.0 <= came_on <= 24.0)): ... You might want to raise an exception from the range-check branch instead of returning a value. And raise an exception from the else-branch, because that branch should never be reached. -- http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
On Tue, Mar 19, 2013 at 12:56 AM, Santosh Kumar wrote: > This simple script is about a public transport, here is the code: > > def report_status(should_be_on, came_on): > if should_be_on < 0.0 or should_be_on > 24.0 or came_on < 0.0 or > came_on > 24.0: > return 'time not in range' > elif should_be_on == came_on: > return 'on time' > elif should_be_on > came_on: > return 'early' > elif should_be_on < came_on: > return 'delayed' > else: > return 'something might be wrong' > > print(report_status(123, 12.0)) Well, for a start, I wouldn't compare for equality there. What's your definition of "on time"? In Melbourne, for instance, a service is deemed "on time" if it's less than 1 minute early and less than 5 minutes late. This is probably too broad, but I would guess that up to 1 minute (or at least half a minute) either side should be considered on time. Are you catering here for custom objects or NaNs that might not be equal, less, or greater? If not, drop the else and just have three branches - for instance: if should_be_on >= came_on + 0.5: # Up to half a minute early is okay return 'early' elif should_be_on <= came_on - 1.0: # Up to one minute late is okay return 'delayed' else: return 'on time' As a matter of readability, incidentally, I'd be inclined to invert the conditions and check the time of arrival against the expected time: if came_on < should_be_on - 0.5: # Up to half a minute early is okay return 'early' elif came_on > should_be_on + 1.0: # Up to one minute late is okay return 'delayed' else: return 'on time' I don't understand your bounds check, though. Are you working with floating point hours in the day? (If so, it's still not necessarily right - it's not uncommon to refer to the hours post-midnight as 24:00, 25:00, etc. But for a toy and a PoC, that would work.) But you then pass the integer 123 as the first arg, which will fail that check. What _is_ your data type? ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
What about this one: if 0.0 < should_be_on > 24.0 or 0.0 < came_on > 24.0: Regards, Laxmikant On 3/18/13, Santosh Kumar wrote: > This simple script is about a public transport, here is the code: > > def report_status(should_be_on, came_on): > if should_be_on < 0.0 or should_be_on > 24.0 or came_on < 0.0 or > came_on > 24.0: > return 'time not in range' > elif should_be_on == came_on: > return 'on time' > elif should_be_on > came_on: > return 'early' > elif should_be_on < came_on: > return 'delayed' > else: > return 'something might be wrong' > > print(report_status(123, 12.0)) > > I am looking forward of make the line starting with `if` short. > > Any tips are welcome. > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
On Mon, 18 Mar 2013 19:28:37 +0530, Laxmikant Chitare wrote:
> Aha, that was smart Chris. Thank you.
>
> But this raises another question in my mind. What is the use case for
> operator.methodcaller ?
The use-case is mostly to allow people to write code in a functional
style, if they so choose.
import operator
func = operator.methodcaller("spam")
items = map(func, [a, b, c, d])
is the functional-style equivalent of:
items = [obj.spam() for obj in [a, b, c, d]]
methodcaller makes a little more sense if you provide arguments:
func = operator.methodcaller("spam", 1, 2, None, "ham")
items = map(func, [a, b, c, d])
compared to:
items = [obj.spam(1, 2, None, "ham") for obj in [a, b, c, d]]
I expect that the methodcaller version will be very slightly faster in
this case, since it doesn't have to parse the arguments every time the
method is called.
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
On Mon, 18 Mar 2013 19:00:15 +0530, Laxmikant Chitare wrote:
> Hi,
>
> I have a program that picks module and method name from a configuration
> file and executes the method. I have found two ways to achieve this.
>
> Apporach 1:
> ---
> moduleName = 'mymodule'#These two variables are read from conf file.
> methodName = 'mymethod'
>
> import operator
> myModule = __import__('mymodule')
> myMethod = operator.methodcaller('mymethod')
> val = myMethod(myModule)
> print val
Since your example code only uses string literals, the best way to write
this would be:
import mymodule
mymodule.mymethod()
But I expect that your example was faulty, and you intended to use
variables:
myModule = __import__(moduleName)
myMethod = operator.methodcaller(methodName)
val = myMethod(myModule)
This would be simpler, and probably faster too:
myModule = __import__(moduleName)
val = getattr(myModule, methodName)()
It's certainly easier to read.
> ---
>
> Apporach 2:
> ---
> moduleName = 'mymodule'#These two variables are read from conf file.
> methodName = 'mymethod'
>
> val = eval('myModule.' + methodName + '()')
> print val
This example also fails, since you don't have anything called "myModule".
I suspect you left out a line, myModule = __import__(moduleName).
> ---
>
> Question: Which approach is better and why. Is there any other better
> way to do this?
You should avoid eval, it is a massive security risk unless you are an
expert, and even then it is still a big security risk. It's also slower
than the alternatives.
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
- Original Message -
> This simple script is about a public transport, here is the code:
>
> def report_status(should_be_on, came_on):
> if should_be_on < 0.0 or should_be_on > 24.0 or came_on < 0.0 or
> came_on > 24.0:
> return 'time not in range'
> elif should_be_on == came_on:
> return 'on time'
> elif should_be_on > came_on:
> return 'early'
> elif should_be_on < came_on:
> return 'delayed'
> else:
> return 'something might be wrong'
>
> print(report_status(123, 12.0))
>
> I am looking forward of make the line starting with `if` short.
>
> Any tips are welcome.
> --
> http://mail.python.org/mailman/listinfo/python-list
You can remove the 'if' line, report_status asks for hours, the caller is
supposed to provide valid hours. What if the caller gives you strings, integer,
floats ? This is a never ending story.
def report_status(should_be_on, came_on):
# well if you really really want to test it
assert(all([int(arg) in range(0,24) for arg in (should_be_on, came_on)]))
return { 0 : 'on time', -1 : 'delayed', 1 : 'early'}[cmp(should_be_on,
came_on)]
JM
Note : in my example, 24.0 is excluded from the valid durations but I think
this is the correct behavior.
-- IMPORTANT NOTICE:
The contents of this email and any attachments are confidential and may also be
privileged. If you are not the intended recipient, please notify the sender
immediately and do not disclose the contents to any other person, use it for
any purpose, or store or copy the information in any medium. Thank you.
--
http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
On Monday, March 18, 2013 9:56:16 AM UTC-4, Santosh Kumar wrote: > This simple script is about a public transport, here is the code: > > > > def report_status(should_be_on, came_on): > > if should_be_on < 0.0 or should_be_on > 24.0 or came_on < 0.0 or > > came_on > 24.0: > > return 'time not in range' > > elif should_be_on == came_on: > > return 'on time' > > elif should_be_on > came_on: > > return 'early' > > elif should_be_on < came_on: > > return 'delayed' > > else: > > return 'something might be wrong' > > > > print(report_status(123, 12.0)) > > > > I am looking forward of make the line starting with `if` short. > > > > Any tips are welcome. If you have a lot of conditions to check, you can't really get around it. -- http://mail.python.org/mailman/listinfo/python-list
Re: "eval vs operator.methodcaller" - which is better?
Thank you Chris, Michel and Steven for your feedback.
Steven, yes I realised that the examples are faulty. I intended to use
variables instead of string literals. I will be careful next time.
On 3/18/13, Steven D'Aprano wrote:
> On Mon, 18 Mar 2013 19:00:15 +0530, Laxmikant Chitare wrote:
>
>> Hi,
>>
>> I have a program that picks module and method name from a configuration
>> file and executes the method. I have found two ways to achieve this.
>>
>> Apporach 1:
>> ---
>> moduleName = 'mymodule'#These two variables are read from conf file.
>> methodName = 'mymethod'
>>
>> import operator
>> myModule = __import__('mymodule')
>> myMethod = operator.methodcaller('mymethod')
>> val = myMethod(myModule)
>> print val
>
> Since your example code only uses string literals, the best way to write
> this would be:
>
> import mymodule
> mymodule.mymethod()
>
> But I expect that your example was faulty, and you intended to use
> variables:
>
> myModule = __import__(moduleName)
> myMethod = operator.methodcaller(methodName)
> val = myMethod(myModule)
>
>
> This would be simpler, and probably faster too:
>
> myModule = __import__(moduleName)
> val = getattr(myModule, methodName)()
>
>
> It's certainly easier to read.
>
>
>> ---
>>
>> Apporach 2:
>> ---
>> moduleName = 'mymodule'#These two variables are read from conf file.
>> methodName = 'mymethod'
>>
>> val = eval('myModule.' + methodName + '()')
>> print val
>
> This example also fails, since you don't have anything called "myModule".
>
> I suspect you left out a line, myModule = __import__(moduleName).
>
>
>> ---
>>
>> Question: Which approach is better and why. Is there any other better
>> way to do this?
>
>
> You should avoid eval, it is a massive security risk unless you are an
> expert, and even then it is still a big security risk. It's also slower
> than the alternatives.
>
>
> --
> Steven
> --
> http://mail.python.org/mailman/listinfo/python-list
>
--
http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
Jussi Piitulainen wrote:
>> Any tips are welcome.
>
> A double tip:
>
> if (not (0.0 <= should_be_on <= 24.0) or
> not (0.0 <= came_on <= 24.0)):
>...
>
Or even:
if not (0.0 <= should_be_on <= 24.0 and 0.0 <= came_on <= 24.0):
...
> You might want to raise an exception from the range-check branch
> instead of returning a value. And raise an exception from the
> else-branch, because that branch should never be reached.
Or even lose the else branch entirely. If the code can never be reached
then don't write it. Also you don't need 'elif' when the individual
branches all return.
Putting that together and allowing some flexibility in the definition of
'on time':
EARLY_DELTA = 1.0/60
LATE_DELTA = 5.0/60
def report_status(should_be_on, came_on):
if not (0.0 <= should_be_on <= 24.0 and 0.0 <= came_on <= 24.0):
raise ValueError('time not in range')
if should_be_on - EARLY_DELTA <= came_on <= should_be_on + LATE_DELTA:
return 'on time'
if came_on > should_be_on:
return 'delayed'
return 'early'
Note that none of this will hande situations around midnight such as:
should_be_on==23.5, came_on=0.5
--
Duncan Booth http://kupuguy.blogspot.com
--
http://mail.python.org/mailman/listinfo/python-list
Re: How to automatically get the indent level from code?
On Sun, Mar 17, 2013 at 1:23 AM, Mark Shroyer wrote:
> I realize this isn't yet precisely what you're asking for, but look at the
> inspect and ast modules:
>
> import ast, inspect
>
> def indent_level():
> lineno = inspect.currentframe().f_back.f_lineno
>
> with open(__file__) as source_file:
> tree = ast.parse(source_file.read(), filename=__file__)
>
> for node in ast.walk(tree):
> if hasattr(node, 'lineno') and node.lineno == lineno:
> return node.col_offset
>
> def example_usage():
> print("first indent_level() = {0}".format(indent_level()))
> if True:
> print("second indent_level() = {0}".format(indent_level()))
>
> if __name__ == '__main__':
> example_usage()
>
> The indent_level function above returns the textual column offset rather than
> the logical block level you're asking for, e.g.:
>
> first indent_level() = 4
> second indent_level() = 8
>
> But hopefully it's a start.
Thanks. I try to run it from stdin. Obviously, it does not work. The
problem is the stdin can not be read again. Is there a way to extend
the code that indentation can be computed even the code is from stdin?
~/linux/test/python/tricks/indent_level$ python - < main.py
Traceback (most recent call last):
File "", line 23, in
File "", line 16, in example_usage
File "", line 8, in indent_level
IOError: [Errno 2] No such file or directory: ''
~/linux/test/python/tricks/indent_level$ cat main.py
#!/usr/bin/env python
import ast, inspect
def indent_level():
lineno = inspect.currentframe().f_back.f_lineno
with open(__file__) as source_file:
tree = ast.parse(source_file.read(), filename=__file__)
for node in ast.walk(tree):
if hasattr(node, 'lineno') and node.lineno == lineno:
return node.col_offset
def example_usage():
print indent_level()
#print("first indent_level() = {0}".format(indent_level()))
if True:
print indent_level()
#print("second indent_level() = {0}".format(indent_level()))
if __name__ == '__main__':
example_usage()
--
Regards,
Peng
--
http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
Duncan Booth writes: > Jussi Piitulainen wrote: > > >> Any tips are welcome. > > > > A double tip: > > > > if (not (0.0 <= should_be_on <= 24.0) or > > not (0.0 <= came_on <= 24.0)): > >... > > > Or even: > > if not (0.0 <= should_be_on <= 24.0 and 0.0 <= came_on <= 24.0): > ... I'd still prefer to split the line, especially considering the fact that the request was to make the line shorter: if not (0.0 <= should_be_on <= 24.0 and 0.0 <= came_on <= 24.0): ... -- http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
On Mon, 18 Mar 2013 15:32:03 +0100, Jean-Michel Pichavant wrote:
> You can remove the 'if' line, report_status asks for hours, the caller
> is supposed to provide valid hours. What if the caller gives you
> strings, integer, floats ? This is a never ending story.
I see you haven't been a programmer very long *wink*
Yes, error checking and data validation is a never ending story. Welcome
to programming. That's what we do.
> def report_status(should_be_on, came_on):
>
> # well if you really really want to test it
> assert(all([int(arg) in range(0,24) for arg in
> (should_be_on, came_on)]))
Please don't use assert for argument checking in public APIs. (And
probably not in private APIs either.) assert is wrong for two reasons:
1) Invalid arguments should raise TypeError or ValueError. You wouldn't
arbitrarily raise KeyError("expected 0 < arg < 24 but got arg = -1") or
IOError("expected an int but got a string"). That would be unprofessional
and foolish. So why raise AssertionError?
2) assert is not guaranteed to run, and you have *no control over it*. If
the user calls python with the -O flag, asserts are disabled and your
error checking is never performed.
assert is designed to verify internal logic of your code, not caller-
facing argument validation.
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
On Mon, 18 Mar 2013 19:26:16 +0530, Santosh Kumar wrote:
> This simple script is about a public transport, here is the code:
>
> def report_status(should_be_on, came_on):
> if should_be_on < 0.0 or should_be_on > 24.0 or came_on < 0.0 or
> came_on > 24.0:
> return 'time not in range'
> elif should_be_on == came_on:
> return 'on time'
> elif should_be_on > came_on:
> return 'early'
> elif should_be_on < came_on:
> return 'delayed'
> else:
> return 'something might be wrong'
Untested, but something like this should work. It adjusts for the times
which fall either side of midnight, it optionally allows for some "slop"
in deciding whether an arrival was on time or not (defaults to 0).
def report(scheduled, actual, slop=0.0):
"""Report whether actual time of arrival is on time, late, early
or cancelled.
Pass actual=None for cancelled services, otherwise both scheduled and
actual must be given as float hours between 0 and 24. E.g. to indicate
a time of 06:30, pass 6.5.
Optional argument slop is a non-negative time in hours which services
are allowed to be late or early and still count as "on time". E.g. if
a service is allowed to arrive with two minutes either side of the
scheduled time and still count as on time, pass slop=2.0/60. The slop
defaults to 0.0.
"""
if not 0 <= scheduled < 24:
raise ValueError('scheduled time out of range')
if not 0 <= slop < 24:
raise ValueError('slop out of range')
if actual is None:
return "service cancelled"
if not 0 <= actual < 24:
raise ValueError('actual arrival time out of range')
diff = actual - scheduled
# Adjust for discontinuity around midnight. We assume that arrivals
# are never more than 12 hours away from their scheduled times.
if diff < -12:
# For example, scheduled=23:55, actual=00:05 gives diff of -23:50
diff += 24
elif diff > 12:
diff -= 24
if diff < -slop:
return "early"
elif diff > slop:
return "late"
else:
return "on time"
One disadvantage with the function as written is that you have to give
times as floats between 0 and 24, instead of a more natural HH:MM syntax.
For example, 11:07am would have to be given as 11.117.
Another weakness is that any slop allowance is symmetrical (e.g. you
can't allow trains to arrive up to one minute early or five minutes late
to be counted as "on time", the two figures have to be equal).
A third weakness is that you can't allow for arrivals more than 12 hours
early or late.
> I am looking forward of make the line starting with `if` short.
:-)
--
Steven
--
http://mail.python.org/mailman/listinfo/python-list
Re: What are some other way to rewrite this if block?
On Tue, Mar 19, 2013 at 2:10 AM, Steven D'Aprano wrote: > A third weakness is that you can't allow for arrivals more than 12 hours > early or late. Oh, but that'll NEVER happen. Oh wait, I've been on a service that was 12 hours late. Is there any chance that you could do your times of arrival and expectation in, say, integer seconds since 1970? ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Excel column 256 limit
Is there some way to go around this limit? I need to import data from python to excel and I need 1440 columns for that. -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel column 256 limit
On 03/18/2013 11:28 AM, Ana Dionísio wrote: Is there some way to go around this limit? I need to import data from python to excel and I need 1440 columns for that. Doesn't sound like a Python question. But one answer is Libre Office Calc, which seems to have a 1024 column limit. -- DaveA -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel column 256 limit
On Mon, 18 Mar 2013 08:28:46 -0700, Ana Dionísio wrote: > Is there some way to go around this limit? I need to import data from > python to excel and I need 1440 columns for that. That's an Excel question, it has nothing to do with Python. Have you considered using something other than Excel? As I understand it, OpenOffice, LibreOffice, and Gnumeric do not have a 256 column limit. Gnumeric is Linux-only, but the other two are available for Windows and Mac, and they are all free, open source software, and they all will read and write Excel spreadsheets. http://openoffice.org/ http://www.libreoffice.org/ http://projects.gnome.org/gnumeric/index.shtml -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel column 256 limit
On 2013-03-18, Dave Angel wrote: > On 03/18/2013 11:28 AM, Ana Dion?sio wrote: > >> Is there some way to go around this limit? I need to import data from >> python to excel and I need 1440 columns for that. > > Doesn't sound like a Python question. But one answer is Libre Office > Calc, which seems to have a 1024 column limit. [I don't see how something with a 1024 column limit is one answer for a requirement of 1440 columns.] IMO, if 256 columns isn't enough, then a spreadsheet probably isn't the right tool. If you need 1440 columns then I can't even imagine a case where a spreadsheet is the right tool. I've seen people spend weeks trying to do something with excel that would have taken a few hours using Numpy/Scipy/Scientific-Python. -- Grant Edwards grant.b.edwardsYow! I want to kill at everyone here with a cute gmail.comcolorful Hydrogen Bomb!! -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
On Sun, Mar 17, 2013 at 11:46 PM, Steven D'Aprano wrote: > I am very interested in this as a concept, although I must admit I'm not > entirely sure what you mean by it. I've read your comment on the link above, > and subsequent emails in this thread, and I'm afraid I don't understand what > you mean here. I feel you are assuming that your readers are already experts > on message-passing languages (Smalltalk?). I know what *I* mean by message > passing, but that's not necessarily what you mean by it. I'm sorry, I haven't been very clear. I'm not even an expert on message-passing languages, but I see that it's a profound concept that hasn't been adequately integrated into the OOP model. In any case, I will try to do better. And I apologize to everyone on the list for the prior mail spam. A part of me is a bit giddy with the idea. By message passing, I mean all the ways we communicate to objects in the OOP environment. Usually we "communicate" to them through method-invokation. But this is the wrong way, I argue, to look at the problem. With function or method syntax, you're telling the computer to "execute something", but that is not the right concepts for OOP. You want the objects to interact with each other and in a high-level language, the syntax should assist with that. > By building it into the language, it would *enforce* a modular object > style, rather than the current, very specialized and very programmer > specific way there is now. In fact, most people never really think in > that paradigm, yet if the language supported/proposed such a syntax, > programmers would start to re-arrange the whole object hierarchy in a > new, more modular and universal way. > [end quote] > > I don't understand this. In what way would message passing enforce a modular > object style? In what way does Python not already have a modular object > style? Hopefully my paragraph clarifies that a bit. But the key conceptual shift is that by enforcing a syntax that moves away from invoking methods and move to message passing between objects, you're automatically enforcing a more modular approach. Mark -- http://mail.python.org/mailman/listinfo/python-list
[Python 3.3.0] Getting tkinter to work on Python 3
Hi. I'm having a problem trying to get this to work well. Basically, whenever I try to import tkinter, this is the issue that I have: >>> import tkinter Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python3.3/tkinter/__init__.py", line 40, in import _tkinter # If this fails your Python may not be configured for Tk ImportError: No module named '_tkinter' I'm running Ubuntu. If I need to provide any further info, please let me know. -- http://mail.python.org/mailman/listinfo/python-list
[Python-ideas] Message passing syntax for objects
> Ian Cordasco wrote: >> >> On Sun, Mar 17, 2013 at 11:53 PM, Mark Janssen >> wrote: >> >>> Hello, >>> >>> I just posted an answers on quora.com about OOP (http://qr.ae/TM1Vb) >>> and wanted to engage the python community on the subject. > > > My answer to that question would be that it *did* > catch on, it's just that we changed the terminology. > Instead of message passing, we talk about calling > methods. Yes, but this is where it breaks the OOP abstraction by 90 degrees. By using function calls, you're telling the machine to do something. But when you want to pass something to an object there should be a natural way to do this for every object. By using methods you pollute the concept space with all sorts of semi-random (i.e. personal) names, like append, add, enqueue, etc. This proposal would not only make a consistent syntax across all objects, but train the programmer to *think* modularly in the sense of having a community of re-usable object. I.e. "What should I do if another object passes me something?". No one thinks this now, because the programmer expects new developers to learn *their* interface! Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
On Mon, Mar 18, 2013 at 10:18 AM, Mark Janssen wrote: >> Ian Cordasco wrote: >>> >>> On Sun, Mar 17, 2013 at 11:53 PM, Mark Janssen >>> wrote: >>> Hello, I just posted an answers on quora.com about OOP (http://qr.ae/TM1Vb) and wanted to engage the python community on the subject. >> >> >> My answer to that question would be that it *did* >> catch on, it's just that we changed the terminology. >> Instead of message passing, we talk about calling >> methods. > > Yes, but this is where it breaks the OOP abstraction by 90 degrees. > By using function calls, you're telling the machine to do something. > But when you want to pass something to an object there should be a > natural way to do this for every object. By using methods you pollute > the concept space with all sorts of semi-random (i.e. personal) names, > like append, add, enqueue, etc. > > This proposal would not only make a consistent syntax across all > objects, but train the programmer to *think* modularly in the sense of > having a community of re-usable object. I.e. "What should I do if > another object passes me something?". No one thinks this now, because > the programmer expects new developers to learn *their* interface! > > Mark > -- You're dreaming of a utopia where computers just read our minds and know what we're thinking. So what if I can pass 42 into an object. What do I intend to happen with that 42? Do I want to add the element to a list? Access the 42nd element? Delete the 42nd element? Let the object pick a behavior at random? Clearly there must be some sort of behavior defined for passing a message into an object. And now we're back to learning the interface that the programmer designed. Only now, instead of having different types of behavior grouped together into classes, we have to use a different object for each operation. So what's the benefit of that over having the object implement the __call__ method? Also, why would we re-use the bit shift operators for message passing? Just because C++ decided to overload the existing operators to mean reading into and writing out of a stream doesn't mean it's a good idea. -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel column 256 limit
On Mon, 18 Mar 2013 16:50:21 +0100, Steven D'Aprano wrote: On Mon, 18 Mar 2013 08:28:46 -0700, Ana Dionísio wrote: Is there some way to go around this limit? I need to import data from python to excel and I need 1440 columns for that. That's an Excel question, it has nothing to do with Python. Have you considered using something other than Excel? As I understand it, OpenOffice, LibreOffice, and Gnumeric do not have a 256 column limit. Just for completeness: Excel in it's "Office 2010" version does not have a 256 column limit either. I can use > 2000 columns without problem. -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python 3.3.0] Getting tkinter to work on Python 3
Seems tkinter is missing in standard installation in ubuntu. Try: sudo apt-get install python3-tk On Mon, Mar 18, 2013 at 6:17 PM, Yves S. Garret wrote: > Hi. I'm having a problem trying to get this to work well. Basically, > whenever I try to > import tkinter, this is the issue that I have: > > >>> import tkinter > Traceback (most recent call last): > File "", line 1, in > File "/usr/local/lib/python3.3/tkinter/__init__.py", line 40, in > import _tkinter # If this fails your Python may not be configured for > Tk > ImportError: No module named '_tkinter' > > I'm running Ubuntu. If I need to provide any further info, please let me > know. > > -- > http://mail.python.org/mailman/listinfo/python-list > > -- Ritchie Flick -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
zipher於 2013年3月19日星期二UTC+8上午1時04分36秒寫道： > On Sun, Mar 17, 2013 at 11:46 PM, Steven D'Aprano wrote: > > > I am very interested in this as a concept, although I must admit I'm not > > > entirely sure what you mean by it. I've read your comment on the link above, > > > and subsequent emails in this thread, and I'm afraid I don't understand what > > > you mean here. I feel you are assuming that your readers are already experts > > > on message-passing languages (Smalltalk?). I know what *I* mean by message > > > passing, but that's not necessarily what you mean by it. > > > > I'm sorry, I haven't been very clear. I'm not even an expert on > > message-passing languages, but I see that it's a profound concept that > > hasn't been adequately integrated into the OOP model. In any case, I > > will try to do better. And I apologize to everyone on the list for > > the prior mail spam. A part of me is a bit giddy with the idea. > > > > By message passing, I mean all the ways we communicate to objects in > > the OOP environment. Usually we "communicate" to them through > > method-invokation. But this is the wrong way, I argue, to look at the > > problem. > > > > With function or method syntax, you're telling the computer to > > "execute something", but that is not the right concepts for OOP. You > > want the objects to interact with each other and in a high-level > > language, the syntax should assist with that. > > > > > By building it into the language, it would *enforce* a modular object > > > style, rather than the current, very specialized and very programmer > > > specific way there is now. In fact, most people never really think in > > > that paradigm, yet if the language supported/proposed such a syntax, > > > programmers would start to re-arrange the whole object hierarchy in a > > > new, more modular and universal way. > > > [end quote] > > > > > > I don't understand this. In what way would message passing enforce a modular > > > object style? In what way does Python not already have a modular object > > > style? > > > > Hopefully my paragraph clarifies that a bit. But the key conceptual > > shift is that by enforcing a syntax that moves away from invoking > > methods and move to message passing between objects, you're > > automatically enforcing a more modular approach. > > > > Mark Please check object pascal and objective c and erlang for the message-action director model of what you want. C is too low level to be suitable for everything. -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
> You're dreaming of a utopia where computers just read our minds and > know what we're thinking. So what if I can pass 42 into an object. > What do I intend to happen with that 42? Do I want to add the element > to a list? Access the 42nd element? Delete the 42nd element? Let the > object pick a behavior at random? Huh?, No the programmer has to think of how data interacts with his/her objects. It's just that *now* the language is wise enough to teach them to think about it. > So > what's the benefit of that over having the object implement the > __call__ method? You bring up an interesting subject. I think you could get rid of the __call__ special method on objects. I think this is the wrong view into the object universe or *data ecosystem*. > Also, why would we re-use the bit shift operators for message passing? > Just because C++ decided to overload the existing operators to mean > reading into and writing out of a stream doesn't mean it's a good > idea. You're right, perhaps there's a better set of symbols that suggest "moving data". Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python 3.3.0] Getting tkinter to work on Python 3
I have. This is what I did and the result that I'm seeing. $ sudo apt-get install python3-tk [sudo] password for ysg: Reading package lists... Done Building dependency tree Reading state information... Done python3-tk is already the newest version. python3-tk set to manually installed. 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded. $ python3 Python 3.3.0 (default, Mar 11 2013, 15:04:13) [GCC 4.5.2] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import tkinter Traceback (most recent call last): File "", line 1, in File "/usr/local/lib/python3.3/tkinter/__init__.py", line 40, in import _tkinter # If this fails your Python may not be configured for Tk ImportError: No module named '_tkinter' >>> :-/ On Mon, Mar 18, 2013 at 2:22 PM, Ritchie Flick wrote: > Seems tkinter is missing in standard installation in ubuntu. Try: > sudo apt-get install python3-tk > > > On Mon, Mar 18, 2013 at 6:17 PM, Yves S. Garret < > yoursurrogate...@gmail.com> wrote: > >> Hi. I'm having a problem trying to get this to work well. Basically, >> whenever I try to >> import tkinter, this is the issue that I have: >> >> >>> import tkinter >> Traceback (most recent call last): >> File "", line 1, in >> File "/usr/local/lib/python3.3/tkinter/__init__.py", line 40, in >> >> import _tkinter # If this fails your Python may not be configured for >> Tk >> ImportError: No module named '_tkinter' >> >> I'm running Ubuntu. If I need to provide any further info, please let me >> know. >> >> -- >> http://mail.python.org/mailman/listinfo/python-list >> >> > > > -- > Ritchie Flick > -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python 3.3.0] Getting tkinter to work on Python 3
"Yves S. Garret" writes: > I have. This is what I did and the result that I'm seeing. > > $ sudo apt-get install python3-tk You installed a "custom" python 3.3, didn't you? So it does not help installing Ubuntu's python3-tk: your python3.3 interpreter won't even look into "system" packages. Most probably, you need to install the proper development libraries and *recompile* the Python 3.3 interpreter: # apt-get install tk-dev ciao, lele. -- nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia. l...@metapensiero.it | -- Fortunato Depero, 1929. -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel column 256 limit
But I still get the error and I use Excel 2010. I'm trying to export data in a list to Excel -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel column 256 limit
Am 18.03.2013 16:28, schrieb Ana Dionísio: Is there some way to go around this limit? I need to import data from python to excel and I need 1440 columns for that. There are many versions of Excel. The recent ones can handle more than 256 columns. If your version doesn't, then Python won't help you to increase this limit... There are many ways to get data from Python into Excel. If you have any specific problems, you should provide more details. Regards, Dietmar -- http://mail.python.org/mailman/listinfo/python-list
Re: Excel column 256 limit
Am 18.03.13 20:00, schrieb Ana Dionísio: But I still get the error and I use Excel 2010. I'm trying to export data in a list to Excel Unless you tell *how exactly* do you export the data into excel format, we probably can't help you. You could try to write a .csv ASCII file, for instance. Christian -- http://mail.python.org/mailman/listinfo/python-list
Re: What am I doing wrong in this simple tkinter example?
On Sun, Mar 17, 2013 at 2:34 AM, Yves S. Garret wrote: > *facepalm* > > Yep, I see it :) . Thanks for your help. Glad to be of service. Welcome to a life of programming, where the palm meets the face on a regular basis... more frequently if you use Microsoft Windows, tar, non-eight-bit-clean transmission methods, or Adobe products, and extremely common as soon as you take over someone else's code [1], but inevitable even without these stimuli. :) Have fun! [1] http://www.dilbert.com/strips/comic/2013-02-24/ ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
8 Dihedral writes: > zipher於 2013年3月19日星期二UTC+8上午1時04分36秒寫道： >> the key conceptual shift is that by enforcing a syntax that moves >> away from invoking methods and move to message passing between >> objects, you're automatically enforcing a more modular approach. > > Please check object pascal and objective c and erlang for > the message-action director model of what you want. I fail to see how syntax differences would change the modularity of your product. The fact that (say) ObjC use the name "message" while Python calls the same a "method" isn't actually changing the concrete fact that both are executing some sort of function that accepts an "instance" object as one of the arguments (in Python, the first parameter, usually called self, in ObjC, and implicit "self"). In other words, the following ObjC [someObj getItemAt: i] is perfectly equivalent to the following Python someObj.getItemAt(i) and to the following Smalltalk someObj getItemAt: i How is the former syntax, where "getItemAt:" is called a "message", more modular from the second, where "getItemAt()" is called a method? ciao, lele. -- nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia. l...@metapensiero.it | -- Fortunato Depero, 1929. -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
On Mon, Mar 18, 2013 at 12:06 PM, Georg Brandl wrote: > Am 18.03.2013 05:26, schrieb Mark Janssen: >> Continuing on this thread, there would be a new bunch of behaviors to >> be defined. Since "everything is an object", there can now be a >> standard way to define the *next* common abstraction of "every object >> interacts with other objects". > > The problem is that for most objects there isn't *the* interaction. Sure, > you could split up complicated objects into small pieces with a smaller > functionality, but at some point you have to stop. Yes. But that is the point, if you look at the quora post -- to invert the object model and create mashups of simple modular data types and working *upwards*. > Let's see how this > concept fares with simple types such as integers or collections... > > 42 >> MyNumberType #would add the integer to your integer type > > That's just random. Why not multiply? Why not exponentiate? Well, as I noted in another post, that while these can be broken down into their simpler component (addition and negative numbers), numbers should probably be treated separately. > 42 >> MyCollectionType #would add the object into your collection: >> *poof*: no more random syntaxiis for putting things in collections.\ > > So you've replaced one method of a collections API by your magical operator, > for all collections. Yes -- for all collections. That's a pretty big gain right? > What about the other methods that are just as important, > such as deleting items, indexing, and querying? The "syntaxitis" would stay > just the same, except if you introduce more operators, which means new syntax > again. > > Also, how would this work for dictionaries or deques? Well, now you get into the Work: a unified data model. Deques, trees, lists, etc were all preliminary evolutionary explorations on this giant computer science journey of knowledge (and data types) which will have to be, can be, pruned and dropped. > MyObject >> # queries the object to output its state. > > What is "its state"? A readable representation? A serialized representation? > A memory dump? That's still for us to decide. We're mastering the OOP paradigm here: What is the ideal object and what is "in common" across all objects? We are Zen, we want to master the notion of object. What is the simplest object model possible without sacrificing critical functionality... > "http://www.cnn.com"; >> MyInternetObject #outputs the HTML text from > CNN's home page. >> >> Each object has to figure out how it will receive things from outside >> of it. Things it can't handle (a string sent to an int) just have to >> be dropped to some other space, much like stderr does within the O.S. >> >> There are probably many other very interesting examples, but the key >> idea I'm working on (as noted in other messages), is a sort-of >> universal language for the internet, a WebOS to be applied to a >> universal data model. > > It seems that you are reinventing pipes (such as UNIX shell pipes). That is a very interesting comparison. That is something like what I'm trying to do. In tandem with the Internet, I do see a kind of synthesis of Web + O.S. integration -- ultimately, creating a "data ecosystem". mark -- http://mail.python.org/mailman/listinfo/python-list
Re: Pygame mouse cursor load/unload
On Saturday, March 2, 2013 7:56:31 PM UTC-6, Alex Gardner wrote: > I am in the process of making a pong game in python using the pygame library. > My current problem is that when I move the mouse, it turns off as soon as > the mouse stops moving. The way I am doing this is by making the default > cursor invisible and using .png files as replacements for the cursor. > Perhaps my code would best explain my problem. I will take help in any way > that I can. Here are the links that contain my code: > > > > Main class: http://pastebin.com/HSQzX6h2 > > Main file (where the problem lies): http://pastebin.com/67p97RsJ > > > > If the links yield nothing, please let me know (agardner...@gmail.com) All is okay save for one thing! I joined the ball and the p1 paddle in the same program. Both of the images flicker to some extent. The paddle itself rarely shows up. I am not quite sure where / when to flip the display :( [ http://pastebin.com/xzMwa85X ] -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
On Mon, Mar 18, 2013 at 1:24 PM, Mark Janssen wrote: > On Mon, Mar 18, 2013 at 12:06 PM, Georg Brandl wrote: >> Am 18.03.2013 05:26, schrieb Mark Janssen: >>> Continuing on this thread, there would be a new bunch of behaviors to >>> be defined. Since "everything is an object", there can now be a >>> standard way to define the *next* common abstraction of "every object >>> interacts with other objects". >> >> The problem is that for most objects there isn't *the* interaction. Sure, >> you could split up complicated objects into small pieces with a smaller >> functionality, but at some point you have to stop. > > Yes. But that is the point, if you look at the quora post -- to > invert the object model and create mashups of simple modular data > types and working *upwards*. > >> Let's see how this >> concept fares with simple types such as integers or collections... >> >> 42 >> MyNumberType #would add the integer to your integer type >> >> That's just random. Why not multiply? Why not exponentiate? > > Well, as I noted in another post, that while these can be broken down > into their simpler component (addition and negative numbers), numbers > should probably be treated separately. > >> 42 >> MyCollectionType #would add the object into your collection: >>> *poof*: no more random syntaxiis for putting things in collections.\ >> >> So you've replaced one method of a collections API by your magical operator, >> for all collections. > > Yes -- for all collections. That's a pretty big gain right? > Nope. No gain at all. Instead of learning the add() method, you learn the >> operator. You have not simplified anything. >> It seems that you are reinventing pipes (such as UNIX shell pipes). > > That is a very interesting comparison. That is something like what > I'm trying to do. In tandem with the Internet, I do see a kind of > synthesis of Web + O.S. integration -- ultimately, creating a "data > ecosystem". > > mark Yes, having the whole program run by chaining functions together is a neat idea. And it works great in functional languages- if you want that as a feature, use OCaml or Haskell. It works less well in imperative languages where you are manipulating data, not just passing it around. > -- > http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Writing Python framework for declarative checks?
HI, NB: I've posted this question on Reddit as well (but didn't get many responses from Pythonistas) - hope it's ok if I post here as well. We currently use a collection of custom Python scripts to validate various things in our production environment/configuration. Many of these are simple XML checks (i.e. validate that the value of this XML tag here equals the value in that file over there). Others might be to check that a host is up, or that this application's crontab start time is within 20 minutes of X, or that a logfile on a server contains a certain line. The checks are executed automatically before every production push. The scripts are written imperatively. E.g.: SSH into a server Open up a file Parse the XML Search for a XML tag Store the value in a variable Compare it to another value somewhere else. I'd like to look at writing a framework to do these validation in a slightly more declarative way - i.e. instead of defining how the server should check something, we should just be able to say value should equal foobar - and let the framework handle the how. I was thinking we could then schedule the checks and shove the jobs onto a queue like Celery. To stop me from re-inventing the wheel - are there any existing projects that do something like this already? Or has anybody here done something similar, or would be able to offer any advice? (I aware of things like Puppet or Chef - or even Salt Stack - however, these are for managing deployments, or actually pushing out configurations. These validation scripts are more to ensure that the configuration changes done by hand are sane, or don't violate certain basic rules). Cheers, Victor -- http://mail.python.org/mailman/listinfo/python-list
The usage of -m option of python
Hi, I don't quite understand how -m option is used. And it is difficult to search for -m in google. Could anybody provide me with an example on how to use this option? Thanks! -m module-name Searches sys.path for the named module and runs the corresponding .py file as a script. -- Regards, Peng -- http://mail.python.org/mailman/listinfo/python-list
Re: The usage of -m option of python
On Tue, Mar 19, 2013 at 8:17 AM, Peng Yu wrote: > Hi, > > I don't quite understand how -m option is used. And it is difficult to > search for -m in google. Could anybody provide me with an example on > how to use this option? Thanks! > >-m module-name > Searches sys.path for the named module and runs the > corresponding .py file as a script. Well, I just searched for 'python m module', but I agree it's not easy. Anyway, Google read my mind and returned this: http://www.python.org/dev/peps/pep-0338/ ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: The usage of -m option of python
>> Hi, >> >> I don't quite understand how -m option is used. And it is difficult to >> search for -m in google. Could anybody provide me with an example on >> how to use this option? Thanks! >> >>-m module-name >> Searches sys.path for the named module and runs the >> corresponding .py file as a script. > I don't quite understand how -m option is used. And it is difficult to > search for -m in google. Could anybody provide me with an example on > how to use this option? Thanks! Forgive me if I'm too verbose: When this module is imported via a regular python import statement, the module's special property ``__name__`` is automatically set to the name of the module, as a string. For example:: >>> import random >>> random.__name__ >>> 'random' If a file is executed as a script from the operating system's command line, the value of the ``__main__`` property is instead automatically set to the string "__main__". This is useful because many python modules have a line such as:: if __name__ == "__main__": # Do something different... # Maybe run some unit tests or something. # Or perhaps parse some command line arguments... This means you can cd into the python modules directory on your system and execute one of the built-in modules directly:: cd /usr/local/lib/python3.3 python3.3 random.py # Tests the random number functions and spits out the result to the # console. We have one file with two behaviors, depending on how it gets executed. You can use the same concept in your own scripts to have both a command line script that does something useful, as well as an importable python module to use in other scripts. Remember, if ``__name__ == "__main__"`` the file is being run as a script. Otherwise it's being imported as a module. So what about that ``-m`` option? Having to cd into the python module directory every time you need to execute a module as a script is cumbersome. The ``-m`` flag is basically a shortcut. These are basically the same:: cd /usr/local/lib/python3.3 python3.3 random.py Same as:: python3.3 -m random #<-- I can do this from any directory. The modules in the standard library have no obligation to do anything useful, or even anything at all, if execute directly but you can use the same idea to execute modules as scripts from packages you create. -Modulok- -- http://mail.python.org/mailman/listinfo/python-list
Re: Pygame mouse cursor load/unload
On Monday, March 18, 2013 3:24:57 PM UTC-5, Alex Gardner wrote: > On Saturday, March 2, 2013 7:56:31 PM UTC-6, Alex Gardner wrote: > > > I am in the process of making a pong game in python using the pygame > > library. My current problem is that when I move the mouse, it turns off as > > soon as the mouse stops moving. The way I am doing this is by making the > > default cursor invisible and using .png files as replacements for the > > cursor. Perhaps my code would best explain my problem. I will take help > > in any way that I can. Here are the links that contain my code: > > > > > > > > > > > > Main class: http://pastebin.com/HSQzX6h2 > > > > > > Main file (where the problem lies): http://pastebin.com/67p97RsJ > > > > > > > > > > > > If the links yield nothing, please let me know (agardner...@gmail.com) > > All is okay save for one thing! I joined the ball and the p1 paddle in the same program. Both of the images flicker to some extent. The paddle itself rarely shows up. I am not quite sure where / when to flip the display :( [ http://pastebin.com/i1GbT6JB ] -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
On Mon, Mar 18, 2013 at 2:51 PM, Andrew Barnert wrote: > Have you even looked at a message-passing language? > > A Smalltalk "message" is a selector and a sequence of arguments. That's what > you send around. Newer dynamic-typed message-passing OO and actor languages > are basically the same as Smalltalk. Yes, but you have to understand that Alan Kays came with strange ideas of some future computer-human symbiosis. So his language design and other similar attempts (like php) is rather skewed from that premise And also, despite name-dropping, I'm not trying to create anything like that idea of message-passing. I'm talking about something very simple, a basic and universal way for objects to communicate. >> With function or method syntax, you're telling the computer to >> "execute something", but that is not the right concepts for OOP. You >> want the objects to interact with each other and in a high-level >> language, the syntax should assist with that. > > And you have to tell the object _how_ to interact with each other. This is a different paradigm that what I'm talking about. In the OOP of my world, Objects already embody the intelligence of how they are going to interact with the outside world, because I put them there. > Even with reasonably intelligent animals, you don't just tell two animals to > interact, except in the rare case where you don't care whether they become > friends or dinner. You're model of computer programming is very alien to me. So I don't think it will be productive to try to convince you of what I'm suggesting, but feel free to continue... Mark -- http://mail.python.org/mailman/listinfo/python-list
Re: Small program ideas
Any other ideas? -- http://mail.python.org/mailman/listinfo/python-list
Re: Small program ideas
On 18/03/2013 23:51, eli m wrote: Any other ideas? How about coming up with a new message passing syntax for objects? I understand from recent postings that this should be fairly easy :) -- Cheers. Mark Lawrence -- http://mail.python.org/mailman/listinfo/python-list
Re: What's the difference between these two uses of "for"?
On Mar 18, 12:33 pm, Roy Smith wrote: > Google's motto may be "don't be evil", but they get to define what evil > is. Apparently working and playing well with mailing list technology > which has worked just fine for literally decades isn't part of the > definition. Their decision to scrap Reader while ploughing forward with this godawful new UI for Groups has pushed them into the "evil" basket for me :( -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python 3.3.0] Getting tkinter to work on Python 3
On Monday, March 18, 2013 2:39:57 PM UTC-4, Lele Gaifax wrote: > "Yves S. Garret" writes: > > > I have. This is what I did and the result that I'm seeing. > > > > $ sudo apt-get install python3-tk > > You installed a "custom" python 3.3, didn't you? So it does not help > installing Ubuntu's python3-tk: your python3.3 interpreter won't even > look into "system" packages. > > Most probably, you need to install the proper development libraries and > *recompile* the Python 3.3 interpreter: > > # apt-get install tk-dev > > ciao, lele. > -- > nickname: Lele Gaifax | Quando vivrò di quello che ho pensato ieri > real: Emanuele Gaifas | comincerò ad aver paura di chi mi copia. > l...@metapensiero.it | -- Fortunato Depero, 1929. Ok, it now seems to work. Weird. I had tk-dev installed (it seems) and then after I re-compiled my interpreter just now, it's working. Thanks for your help. -- http://mail.python.org/mailman/listinfo/python-list
Problem this random seed()
Hello everyone, i am using the MMK.py example from a SimPy tutorial, which can be found here: http://heather.cs.ucdavis.edu/~matloff/156/PLN/DESimIntro.pdf I have made very little changes to the code and i have upload it here: http://codeviewer.org/view/code:30d3 The problem is that i am executing the main() function in lines 83 and 90, but i do not receive the same result, although the random seed is used in the G class. Any idea please, how can i solve it ? Thanks, Nicholas. -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem this random seed()
On Monday, March 18, 2013 6:57:30 PM UTC-7, NZach wrote: > Hello everyone, > > > > i am using the MMK.py example from a SimPy tutorial, which can be found here: > http://heather.cs.ucdavis.edu/~matloff/156/PLN/DESimIntro.pdf > > > > I have made very little changes to the code and i have upload it here: > > http://codeviewer.org/view/code:30d3 > > > > The problem is that i am executing the main() function in lines 83 and 90, > but > > i do not receive the same result, although the random seed is used in the G > > class. > > > > Any idea please, how can i solve it ? > > > > > > Thanks, > > > > Nicholas. What errors did it show? -- http://mail.python.org/mailman/listinfo/python-list
How avoid installing directories match some pattern when using distutils.core setup?
Hi, By default, setup.py will install everything in the source directory. I want mask some directories so that they will not be installed. Is there a way to do so in setup.py? -- Regards, Peng -- http://mail.python.org/mailman/listinfo/python-list
Re: Problem this random seed()
On Mar 19, 11:57 am, NZach wrote: > The problem is that i am executing the main() function in lines 83 and 90, > but > i do not receive the same result, although the random seed is used in the G > class. > > Any idea please, how can i solve it ? The seed is used to create a Random instance at the very start of the module. This means it will have the same state for each run of the module, but not for each execution of the main function. To have each execution of main() return the same result, you will need to set the seed _within_ the main function. Try adding this as the first line in main: G.Rnd = Random(12345) This should ensure that the state of your random generator is the same for each execution of the main() function and any subsequent functions it calls that rely on G.Rnd. -- http://mail.python.org/mailman/listinfo/python-list
Re: The usage of -m option of python
On 3/18/2013 5:17 PM, Peng Yu wrote: Hi, I don't quite understand how -m option is used. And it is difficult to search for -m in google. Could anybody provide me with an example on how to use this option? python -m test at a command line runs the regression tests in the test package python -m test -v test_difflib runs test.test_difflib in verbose mode. These are alternatives to python ... Python just searches for module itself, same as for import, but executes it as main module instead of importing. This is really handy for developers running tests, where path-to-test is not only a nuisance to type, but different for development builds than for installations, and of course, different for each version. Let python find the /Lib corresponding to the executable. I am not sure if it works for things outside /Lib -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: "Learn Python Quickly" is FREE today March 18th
On 3/18/2013 8:55 AM, John Rowland wrote: For just today, the book "Learn Python Quickly" is free to download from Amazon. Also, go to www.learnpythonquickly.com for more information. I just 'bought' this to see if it is something I would recommend. I turned first to the IDLE section. A couple of suggestions: "Click Run -> Run Module F5 The following window will appear " That soon gets to be a nuisance and can be turned off with Options / Configure IDLE / General / Autosave Preferences (x) No prompt. I think even beginners should learn about the configure dialog. "It is essential that you include the .py extension." We fixed that nuisance last summer for 3.3. So: "For python versions before 3.3, " -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python-ideas] Message passing syntax for objects
From: Mark Janssen Sent: Monday, March 18, 2013 4:41 PM > On Mon, Mar 18, 2013 at 2:51 PM, Andrew Barnert > wrote: >> Have you even looked at a message-passing language? >> >> A Smalltalk "message" is a selector and a sequence of arguments. > That's what you send around. Newer dynamic-typed message-passing OO and > actor languages are basically the same as Smalltalk. > > Yes, but you have to understand that Alan Kays came with strange ideas > of some future computer-human symbiosis. So his language design and > other similar attempts (like php) is rather skewed from that premise The idea that message passing is fundamentally different from method calling also turned out to be one of those strange ideas, since it only took a couple years to prove that they are theoretically completely isomorphic—and, for that matter, they're both isomorphic to closures. > And also, despite name-dropping, I'm not trying to create anything > like that idea of message-passing. I'm talking about something very > simple, a basic and universal way for objects to communicate. Message passing is a simple, basic, and universal way for objects to communicate. Everything from dot-syntax method calls to JSON RPC protocols can be modeled as passing messages. But what you're talking about isn't message passing. The idea that messages have names, and reference objects as arguments, is fundamental, and by leaving that out, you're talking about something different. In effect, your "objects" are just single-parameter functions, and your "messages" are the call operator. >>> With function or method syntax, you're telling the computer to >>> "execute something", but that is not the right concepts for > OOP. You >>> want the objects to interact with each other and in a high-level >>> language, the syntax should assist with that. >> >> And you have to tell the object _how_ to interact with each other. > > This is a different paradigm that what I'm talking about. In the OOP > of my world, Objects already embody the intelligence of how they are > going to interact with the outside world, because I put them there. The paradigm you're talking about is useless. You have lists that know how to append, but don't know how to get/search/iterate. Almost every useful object needs the intelligence to interact with the world in two or more ways. >> Even with reasonably intelligent animals, you don't just tell two > animals to interact, except in the rare case where you don't care whether > they become friends or dinner. > > You're model of computer programming is very alien to me. So I don't > think it will be productive to try to convince you of what I'm > suggesting, but feel free to continue... My model of (object-oriented) computer programming is that programming objects model objects which have a variety of behaviors, each of which is triggered by sending a different message. This is pretty much the central definition that everyone who programs or theorizes about programming uses. If you read any textbook, wiki page, journal article, or tutorial, they're all talking about that, or something directly isomorphic to it. If that's alien to you, then object-oriented programming is alien to you. -- http://mail.python.org/mailman/listinfo/python-list
Re: [Python 3.3.0] Getting tkinter to work on Python 3
On 3/18/2013 9:52 PM, Yves S. Garret wrote: Ok, it now seems to work. Weird. I had tk-dev installed (it seems) and then after I re-compiled my interpreter just now, it's working. If your previous compilation was before tk-dev was installed, it will not have compiled _tkinter properly. On PC, one also has to re-compile after doing equivalent of downloading tk-dev. -- Terry Jan Reedy -- http://mail.python.org/mailman/listinfo/python-list
