Re: OO and game design questions
On Oct 19, 8:08 pm, Carl Banks wrote: > On Oct 19, 1:19 am, dex wrote: > > > > > > > > I'm not sure if it's a good idea to let an item disappear from your > > > inventory by a weak reference disappearing. It seems a little shaky > > > to not know where your objects are being referenced, but that's yout > > > decision. > > > OK, imagine a MUD, where players can "dig out" new rooms. Room A has a > > door that holds reference to newly created room B. By "using" a door, > > player is transported to room B. At later time someone destroys room > > B. > > > Using strong references, I have to remove room B from list of rooms, > > and also remove door to room B, as it holds reference to room B. To do > > that, I have to keep list of doors that lead to room B. > > > Using weak references, I don't have to worry about removing all doors > > to room B. They all now have a dead reference, which better models > > actual situation. If part of mine collapses, or if a module on space > > station is destroyed, the passage to that location does not magically > > vanish - it's just obstructed. > > > Can you please tell me if there's something wrong with my reasoning? > > Well, you're talking about particulars here whereas I am speaking in > general. If something is "questionable" or even "bad" in general it > doesn't mean there are no particular cases for it. > > Generally speaking: in a game there's presumably some conservation of > objects. If you drop an item, does it disappear, or does it become an > object of the room? Weak referencing won't help you in the latter > case because you have to take care of references at both ends anyway. > That's what I mean by shaky: it lets you forget about half of the > transaction, which might not be the best thing. YMMV > > Carl Banks I see your point. I'll think this through and try to build more robust system. Thanks for your insight. -- http://mail.python.org/mailman/listinfo/python-list
Re: OO and game design questions
On Oct 19, 6:54 pm, Dennis Lee Bieber wrote: > On Tue, 19 Oct 2010 01:19:48 -0700 (PDT), dex > declaimed the following in gmane.comp.python.general: > > > > > OK, imagine a MUD, where players can "dig out" new rooms. Room A has a > > door that holds reference to newly created room B. By "using" a door, > > player is transported to room B. At later time someone destroys room > > B. > > Out of curiosity, have you looked at any of the older Python > efforts? > > http://py-universe.sourceforge.net/http://www.strout.net/info/coding/python/poo/index.html(some > dead > links) > -- > Wulfraed Dennis Lee Bieber AF6VN > wlfr...@ix.netcom.com HTTP://wlfraed.home.netcom.com/ I will check out your links. I did some research on several MUD projects (evennia, PyMUD) and gained very little from them. I used MUD only as example, my game idea is combination of Rogue and Elite, with Darklands GUI. It's definitely overambitious, but I'm taking it slowly and learning things on the way. Thanks for input. -- http://mail.python.org/mailman/listinfo/python-list
Re: merge list of tuples with list
>On Wed, Oct 20, 2010 at 1:33 PM, Daniel Wagner > wrote: >> Any more efficient ways or suggestions are still welcome! In article James Mills wrote: >Did you not see Paul Rubin's solution: > [x+(y,) for x,y in zip(a,b)] > [(1, 2, 3, 7), (4, 5, 6, 8)] > >I think this is much nicer and probably more efficient. For a slight boost in Python 2.x, use itertools.izip() to avoid making an actual list out of zip(a,b). (In 3.x, "plain" zip() is already an iterator rather than a list-result function.) This method (Paul Rubin's) uses only a little extra storage, and almost no extra when using itertools.izip() (or 3.x). I think it is more straightforward than multi-zip-ing (e.g., zip(*zip(*a) + [b])) as well. The two-zip method needs list()-s in 3.x as well, making it clearer where the copies occur: list(zip(*a)) makes the list [(1, 4), (2, 5), (3, 6)] [input value is still referenced via "a" so sticks around] [b] makes the tuple (7, 8) into the list [(7, 8)] [input value is still referenced via "b" so sticks around] + adds those two lists producing the list [(1, 4), (2, 5), (3, 6), (7, 8)] [the two input values are no longer referenced and are thus discarded] list(zip(*that)) makes the list [(1, 2, 3, 7), (4, 5, 6, 8)] [the input value -- the result of the addition in the next to last step -- is no longer referenced and thus discarded] All these temporary results take up space and time. The list comprehension simply builds the final result, once. Of course, I have not used timeit to try this out. :-) Let's do that, just for fun (and to let me play with timeit from the command line): (I am not sure why I have to give the full path to the timeit.py source here) sh-3.2$ python /System/Library/Frameworks/Python.framework/\ Versions/2.5/lib/python2.5/timeit.py \ 'a=[(1,2,3),(4,5,6)];b=(7,8);[x+(y,) for x,y in zip(a,b)]' 10 loops, best of 3: 2.55 usec per loop sh-3.2$ python [long path snipped] \ 'a=[(1,2,3),(4,5,6)];b=(7,8);[x+(y,) for x,y in zip(a,b)]' 10 loops, best of 3: 2.56 usec per loop sh-3.2$ python [long path snipped] \ 'a=[(1,2,3),(4,5,6)];b=(7,8);zip(*zip(*a) + [b])' 10 loops, best of 3: 3.84 usec per loop sh-3.2$ python [long path snipped] \ 'a=[(1,2,3),(4,5,6)];b=(7,8);zip(*zip(*a) + [b])' 10 loops, best of 3: 3.85 usec per loop Hence, even in 2.5 where zip makes a temporary copy of the list, the list comprehension version is faster. Adding an explicit use of itertools.izip does help, but not much, with these short lists: sh-3.2$ python ... -s 'import itertools' \ 'a=[(1,2,3),(4,5,6)];b=(7,8);[x+(y,) for x,y in itertools.izip(a,b)]' 10 loops, best of 3: 2.27 usec per loop sh-3.2$ python ... -s 'import itertools' \ 'a=[(1,2,3),(4,5,6)];b=(7,8);[x+(y,) for x,y in itertools.izip(a,b)]' 10 loops, best of 3: 2.29 usec per loop (It is easy enough to move the assignments to a and b into the -s argument, but it makes relatively little difference since the list comprehension and two-zip methods both have the same setup overhead. The "import", however, is pretty slow, so it is not good to repeat it on every trip through the 10 loops -- on my machine it jumps to 3.7 usec/loop, almost as slow as the two-zip method.) -- In-Real-Life: Chris Torek, Wind River Systems Salt Lake City, UT, USA (40°39.22'N, 111°50.29'W) +1 801 277 2603 email: gmail (figure it out) http://web.torek.net/torek/index.html -- http://mail.python.org/mailman/listinfo/python-list
Python debug assertion
Python disables MSCRT assertions for debug mode in the initialization of exceptions module. Does anyone know why? -- http://mail.python.org/mailman/listinfo/python-list
Re: merge list of tuples with list
Daniel Wagner wrote: > Hello Everyone, > > I'm new in this group and I hope it is ok to directly ask a question. > > My short question: I'm searching for a nice way to merge a list of > tuples with another tuple or list. Short example: > a = [(1,2,3), (4,5,6)] > b = (7,8) > > After the merging I would like to have an output like: > a = [(1,2,3,7), (4,5,6)] > > It was possible for me to create this output using a "for i in a" > technique but I think this isn't a very nice way and there should > exist a solution using the map(), zip()-functions > > I appreciate any hints how to solve this problem efficiently. >>> from itertools import starmap, izip >>> from operator import add >>> a = [(1,2,3), (4,5,6)] >>> b = (7,8) >>> list(starmap(add, izip(a, izip(b [(1, 2, 3, 7), (4, 5, 6, 8)] This is likely slower than the straightforward [x + (y,) for x, y in zip(a, b)] for "short" lists, but should be faster for "long" lists. Of course you'd have to time-it to be sure. You should also take into consideration that the latter can be understood immediately by any moderately experienced pythonista. Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: Reading Outlook .msg file using Python
On 19/10/2010 22:48, John Henry wrote: Looks like this flag is valid only if you are getting messages directly from Outlook. When reading the msg file, the flag is invalid. Same issue when accessing attachments. In addition, the MAPITable method does not seem to work at all when trying to get attachments out of the msg file (works when dealing with message in an Outlook mailbox). Eitherway, the display_name doesn't work when trying to display the filename of the attachment. I was able to get the date by using the PR_TRANSPORT_MESSAGE_HEADERS mapitags Ah, thanks. As you will have realised, my code is basically geared to reading an Outlook/Exchange message box. I hadn't really tried it on individual message files, except my original excerpt. If it were opportune, I'd be interested in seeing your working code. TJG -- http://mail.python.org/mailman/listinfo/python-list
Re: ANN: Python-on-a-Chip release 09
dwhall, 18.10.2010 15:15: Python-on-a-Chip Featuring the PyMite VM === [...] Python-on-a-Chip (p14p) is a project to develop a reduced Python virtual machine (codenamed PyMite) that runs a significant subset of the Python language on microcontrollers without an OS. Do you have any idea of how fast it is compared to CPython when run on a "normal" CPU? Given the size indications of a few KB of required memory, the entire runtime should easily fit into a couple of cache lines of the CPU's L1 cache, which could be quite an advantage, at least for selected use cases. I assume it also uses unboxed (plain integer/float) arithmetic, right? Does that make a difference? Stefan -- http://mail.python.org/mailman/listinfo/python-list
Re: OO and game design questions
On Oct 18, 8:28 am, dex wrote: > I'm building a turn based RPG game as a hobby. The design is becoming > increasingly complicated and confusing, and I think I may have > tendency to over-engineer simple things. Can anybody please check my > problems-solutions and point me to more elegant solution? > > Every item/character/room is a separate object. Items/characters need > to have references to room they are in, and room needs to have a list > of references to items/characters that are contained within. I decided > to use weak references. That way I can destroy object by deleting it, > I don't have to destroy all references as well. In each object's > __init__() that object is added to game_object list, and in each > __del__() they are removed from game_object list. This mechanism keeps > them safe from garbage collector. How pythonic is this design? > > In turn-based games, the order of action execution in battle can give > unfair advantage to players. For example, if player's arm is crippled > before his action is executed, he would do less damage. To offset > this, I first execute all players' actions and calculate effects in > first pass, then apply the effects in second pass. The effect can be > health decrease by 15HP, item pick-up, 30p experience gain, etc. This > means the player deals the same amount of damage no matter what > happens to him in that turn. The difficult part is keeping track of > various effects. I had to make separate class for various types of > effects (ChangeAttributeEffect, GetItemEffect, LooseItemEffect). Each > class stores weak reference to target object and has apply() method > that applies the effect to object. I'm not satisfied with this as it's > limiting, error-prone and uses metaprogramming. Is there a design > pattern that would remember changes to an object, and apply them > later? > > Sorry for the wall of text. One common way to store delayed actions is as a lambda (an anonymous function.) A lambda defines a new function: , and you can call this function later. The created function has no name, (but you can assign it to a variable to give it a name if you like) and can be called later: So in the game, you could have a collection 'effects', each one will be a lambda: effects = [] At the start of the round, as each entity makes its moves, they add lambdas to this collection. effects.append( lambda: decrease_hp(monster_a, 4) ) effects.append( lambda: lose_item(monster_a, item_b) ) Instead of appending it directly like this, I imagine the lambdas could be returned by the monster's 'act' or 'update' method: class Monster(): def act(self): # blah and finally return lambda: decrease_hp(monster_a, 4) Then for the start of a round, first you ask each monster what action it is going to perform: for monster in room.monsters: effects.append( monster.act() ) Then for the end of the round, call all the lambdas for effect in effects: effect() -- http://mail.python.org/mailman/listinfo/python-list
Re: OO and game design questions
On Oct 20, 11:25 am, Jonathan Hartley wrote: > On Oct 18, 8:28 am, dex wrote: > > > > > I'm building a turn based RPG game as a hobby. The design is becoming > > increasingly complicated and confusing, and I think I may have > > tendency to over-engineer simple things. Can anybody please check my > > problems-solutions and point me to more elegant solution? > > > Every item/character/room is a separate object. Items/characters need > > to have references to room they are in, and room needs to have a list > > of references to items/characters that are contained within. I decided > > to use weak references. That way I can destroy object by deleting it, > > I don't have to destroy all references as well. In each object's > > __init__() that object is added to game_object list, and in each > > __del__() they are removed from game_object list. This mechanism keeps > > them safe from garbage collector. How pythonic is this design? > > > In turn-based games, the order of action execution in battle can give > > unfair advantage to players. For example, if player's arm is crippled > > before his action is executed, he would do less damage. To offset > > this, I first execute all players' actions and calculate effects in > > first pass, then apply the effects in second pass. The effect can be > > health decrease by 15HP, item pick-up, 30p experience gain, etc. This > > means the player deals the same amount of damage no matter what > > happens to him in that turn. The difficult part is keeping track of > > various effects. I had to make separate class for various types of > > effects (ChangeAttributeEffect, GetItemEffect, LooseItemEffect). Each > > class stores weak reference to target object and has apply() method > > that applies the effect to object. I'm not satisfied with this as it's > > limiting, error-prone and uses metaprogramming. Is there a design > > pattern that would remember changes to an object, and apply them > > later? > > > Sorry for the wall of text. > > One common way to store delayed actions is as a lambda (an anonymous > function.) A lambda defines a new function: > > , and you can call this function later. The created function has no > name, (but you can assign it to a variable to give it a name if you > like) and can be called later: > > So in the game, you could have a collection 'effects', each one will > be a lambda: > > effects = [] > > At the start of the round, as each entity makes its moves, they add > lambdas to this collection. > > effects.append( > lambda: decrease_hp(monster_a, 4) > ) > effects.append( > lambda: lose_item(monster_a, item_b) > ) > > Instead of appending it directly like this, I imagine the lambdas > could be returned by the monster's 'act' or 'update' method: > > class Monster(): > def act(self): > # blah and finally > return lambda: decrease_hp(monster_a, 4) > > Then for the start of a round, first you ask each monster what action > it is going to perform: > > for monster in room.monsters: > effects.append( > monster.act() > ) > > Then for the end of the round, call all the lambdas > > for effect in effects: > effect() Also, I second other people's suggestions that you almost never need to be using __del__ nor weak references in Python, unless you are writing a project that is specifically related to complex resource allocation issues. In an rpg game like this, just store references to the objects that you need (which you have to do anyway, to use them), and forget about allocation issues. Don't be afraid to post follow-up questions, (or even to mail me off list.) I make hobbyist OpenGL games in Python myself, and although I'm no expert, I'd love to chat more about this for our mutual benefit. -- http://mail.python.org/mailman/listinfo/python-list
Re: pylint -- should I just ignore it sometimes?
Seebs wrote:
On 2010-10-19, Martin P. Hellwig wrote:
Speaking without context here, so take it with as much salt as required
;-), it is not that unusual. However there are some things to consider,
for example are all these attributes related to each other? If so
wouldn't it be more pythonic to have one attribute which is a dictionary
and store your stuff in there?
I don't know. Does "pythonic" mean "needlessly verbose"? :)
I did, in an early draft, have something that basically came down to:
self.foo = {}
self.foo['a'] = a()
self.foo['b'] = b()
and then I realized that I could just write:
self.a = a()
self.b = b()
and spend a lot less extra typing on repeating something that, by virtue
of being repeated constantly, was therefore meaningless. It wasn't creating
a meaningful distinction, it wasn't showing a meaningful relationship...
All these things are attributes of the thing itself, not attributes of its
dictionary.
Difficult to argue about meaning when you give a meaningless example :)
The question you have to answer is : "Is a and b attributes of self
(whatever that is)".
Actually everything should be driven by its meaning, not if it's quicker
to write or something like that.
Regarding the first question about ignoring pylint:
It's a tool, and requires a lot of configuration.
1/ define *your* coding rules (PEP 8 is just one coding rule among the
others, it's only required if you want to commit into the standard library)
2/ When you know about your rules then configure pylint so it suits with
those rules.
3/ Never ignore a defect reported by pylint. If a pylint rule does not
satisfy you, disable it so pylint stops reporting it.
except ValueError, e:
Use meaningful names, this is so important. 'e' is not meaningful.
'exception' would be slighly better. On that particular case, pylint is
right to complain. When dealing with such issue like "I'm too lazy to
write proper engligh" always think that what is the most important thing
is to save the Reader's time, not the Writer's time. Using 'e' would
force to reader to introspect to code to get an idea of what 'e' is.
Moreover, code completion makes use of long names costless.
You should read this very good paper about naming:
http://tottinge.blogsome.com/meaningfulnames/
JM
--
http://mail.python.org/mailman/listinfo/python-list
Re: OO and game design questions
On Oct 20, 12:25 pm, Jonathan Hartley wrote: > On Oct 18, 8:28 am, dex wrote: > > > > > > > I'm building a turn based RPG game as a hobby. The design is becoming > > increasingly complicated and confusing, and I think I may have > > tendency to over-engineer simple things. Can anybody please check my > > problems-solutions and point me to more elegant solution? > > > Every item/character/room is a separate object. Items/characters need > > to have references to room they are in, and room needs to have a list > > of references to items/characters that are contained within. I decided > > to use weak references. That way I can destroy object by deleting it, > > I don't have to destroy all references as well. In each object's > > __init__() that object is added to game_object list, and in each > > __del__() they are removed from game_object list. This mechanism keeps > > them safe from garbage collector. How pythonic is this design? > > > In turn-based games, the order of action execution in battle can give > > unfair advantage to players. For example, if player's arm is crippled > > before his action is executed, he would do less damage. To offset > > this, I first execute all players' actions and calculate effects in > > first pass, then apply the effects in second pass. The effect can be > > health decrease by 15HP, item pick-up, 30p experience gain, etc. This > > means the player deals the same amount of damage no matter what > > happens to him in that turn. The difficult part is keeping track of > > various effects. I had to make separate class for various types of > > effects (ChangeAttributeEffect, GetItemEffect, LooseItemEffect). Each > > class stores weak reference to target object and has apply() method > > that applies the effect to object. I'm not satisfied with this as it's > > limiting, error-prone and uses metaprogramming. Is there a design > > pattern that would remember changes to an object, and apply them > > later? > > > Sorry for the wall of text. > > One common way to store delayed actions is as a lambda (an anonymous > function.) A lambda defines a new function: > > , and you can call this function later. The created function has no > name, (but you can assign it to a variable to give it a name if you > like) and can be called later: > > So in the game, you could have a collection 'effects', each one will > be a lambda: > > effects = [] > > At the start of the round, as each entity makes its moves, they add > lambdas to this collection. > > effects.append( > lambda: decrease_hp(monster_a, 4) > ) > effects.append( > lambda: lose_item(monster_a, item_b) > ) > > Instead of appending it directly like this, I imagine the lambdas > could be returned by the monster's 'act' or 'update' method: > > class Monster(): > def act(self): > # blah and finally > return lambda: decrease_hp(monster_a, 4) > > Then for the start of a round, first you ask each monster what action > it is going to perform: > > for monster in room.monsters: > effects.append( > monster.act() > ) > > Then for the end of the round, call all the lambdas > > for effect in effects: > effect() Mr. Roy Smith already proposed using closures. I already did a similar thing in my code, but instead of decrease_hp() I have AttributeEffect class which is able to modify any attribute (in old RPGs some monsters could drain your intelligence, in my game laser gun hit will decrease HP as well as armor integrity). The first version looks like this (missing few checks): class AttributeEffect(object): '''Effect changes object's attribute by delta''' def __init__(self, obj, attrib, delta): self.obj = obj # reference to object the effect applies to self.attrib = attrib # name of attribute that effect applies to self.delta = delta # change of value for object.attribute def apply(self): value = getattr(self.obj, self.attrib) # todo: try, except value += self.delta setattr(self.obj(), self.attrib, value) Yesterday I learned that Python 3.0 introduces nonlocal keyword which would simplify defining effect functions and passing them along. Nice improvement. -- http://mail.python.org/mailman/listinfo/python-list
how to name a function in a comp lang (design)
A great piece about terminology in computer languages. * 〈The Poetry of Function Naming〉 (2010-10-18) By Stephen Wolfram. At: http://blog.stephenwolfram.com/2010/10/the-poetry-of-function-naming/ See also: • 〈The Importance of Terminology's Quality In Computer Languages〉 http://xahlee.org/UnixResource_dir/writ/naming_functions.html where i gave some examples of the naming. Xah ∑ http://xahlee.org/ ☄ -- http://mail.python.org/mailman/listinfo/python-list
Re: Windows: getting notification about power state changes
Hi Tim, Thanks a lot. I'll look into it. On 10/19/2010 11:30 AM, Tim Golden wrote: > On 19/10/2010 10:06, Gelonida wrote: >> I'd like to be notified about certain events and call certain python >> functions depending on the event. >> >> call a function: >> - before (or after) the screen saver kicks in . . . >> - before (or after) the screen saver was stopped > > This should take you a certain amount of the way: > > http://timgolden.me.uk/python/win32_how_do_i/track-session-events.html > > I honestly don't know if the OS even knows when the monitor's > switched on / when the disk is spun up. > > WMI has some power events: > > http://msdn.microsoft.com/en-us/library/aa394362%28v=VS.85%29.aspx > > > http://timgolden.me.uk/python/wmi/cookbook.html#monitor-multiple-machines-for-power-events > > -- http://mail.python.org/mailman/listinfo/python-list
Re: Python3: Is this a bug in urllib?
Johannes Bauer wrote:
> Hi,
>
> I've experienced the following behavior with Python3 of which I do not
> know if it's a bug or not. On two Python3.1 implementations, Python's
> urllib hangs when encountering a HTTP 301 (Redirect).
>
> The code to reproduce is a one-liner (actually, two-liner), Python from
> Ubuntu tree:
>
> Python 3.1.2 (r312:79147, Apr 15 2010, 15:35:48)
> [GCC 4.4.3] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
from urllib import request;
request.URLopener().open("http://google.de";)
>
> Also occurs on another Python version (Gentoo):
>
> Python 3.1.2 (release31-maint, Jun 9 2010, 23:58:21)
> [GCC 4.3.4] on linux2
>
> The exchanged HTTP is:
>
> GET http://google.de HTTP/1.1
> Accept-Encoding: identity
> Host: google.de
> User-Agent: Python-urllib/3.1
>
> HTTP/1.1 301 Moved Permanently
> Via: 1.1 IMMPWISA01
> Connection: Keep-Alive
> Proxy-Connection: Keep-Alive
> Content-Length: 218
> Expires: Thu, 18 Nov 2010 15:18:40 GMT
> Date: Tue, 19 Oct 2010 15:18:40 GMT
> Location: http://www.google.de/
> Content-Type: text/html; charset=UTF-8
> Server: gws
> Cache-Control: public, max-age=2592000
> X-XSS-Protection: 1; mode=block
>
> content="text/html;charset=utf-8">
> 301 Moved
> 301 Moved
> The document has moved
> http://www.google.de/";>here.
>
>
> Although the content might indicate looping forever, it just hangs with
> no web traffic whatsoever (the TCP connection stays open, however).
>
> When interrupting with Ctrl-C, this is the calltrace:
>
> Traceback (most recent call last):
> File "", line 1, in
> File "/usr/lib/python3.1/urllib/request.py", line 1454, in open
> return getattr(self, name)(url)
> File "/usr/lib/python3.1/urllib/request.py", line 1628, in open_http
> return self._open_generic_http(http.client.HTTPConnection, url, data)
> File "/usr/lib/python3.1/urllib/request.py", line 1624, in
> _open_generic_http
> response.status, response.reason, response.msg, data)
> File "/usr/lib/python3.1/urllib/request.py", line 1644, in http_error
> return self.http_error_default(url, fp, errcode, errmsg, headers)
> File "/usr/lib/python3.1/urllib/request.py", line 1648, in
> http_error_default
> void = fp.read()
> File "/usr/lib/python3.1/socket.py", line 214, in readinto
> return self._sock.recv_into(b)
> KeyboardInterrupt
>
> Can anyone tell me if this is a bug or expected behavior?
While I'm not 100 percent sure it looks like a bug to me and I think you
should report it at http://bugs.python.org
Peter
--
http://mail.python.org/mailman/listinfo/python-list
Re: how to name a function in a comp lang (design)
Am 20.10.2010 13:14, schrieb Xah Lee: See also: • 〈The Importance of Terminology's Quality In Computer Languages〉 http://xahlee.org/UnixResource_dir/writ/naming_functions.html where i gave some examples of the naming. Xah ∑ http://xahlee.org/ ☄ "I'd like to introduce a blog post by Stephen Wolfram, on the design process of Mathematica. In particular, he touches on the importance of naming of functions." "The functions in Mathematica, are usually very well-named, in contrast to most other computing languages." "Let me give a few example. [...]" It is much easier to improve something good than to invent from scratch. When Lisp was born, Stephen Wolfram was still wearing diapers. For your information: Mathematica was my first Lisp-like language. I used it about 10 years almost every day and I love it because of the beauty of the concept. But Mathematica has two serious problems: first, there is only one implementation and it is commercial, and secondly, Mathematica is very, very slowly and does not generate executable code that can be used without Mathematica itself. Thus, comparisons to other languages, such as Lisp are not fair. regards Marc -- http://mail.python.org/mailman/listinfo/python-list
Re: how to name a function in a comp lang (design)
On Oct 20, 4:52 am, Marc Mientki wrote: > Am 20.10.2010 13:14, schrieb Xah Lee: > > > See also: > > > • 〈The Importance of Terminology's Quality In Computer Languages〉 > >http://xahlee.org/UnixResource_dir/writ/naming_functions.html > > > where i gave some examples of the naming. > > "I'd like to introduce a blog post by Stephen Wolfram, on the design > process of Mathematica. In particular, he touches on the importance of > naming of functions." > > "The functions in Mathematica, are usually very well-named, in > contrast to most other computing languages." > > "Let me give a few example. [...]" thanks for your post. didn' t know you also use Mathematica. on the aspect of function naming, i think Mathematica is rather unique in its philosophy. Am not aware any other lang old or new follows a similar philosophy... possibly except javascript. > It is much easier to improve something good than to invent from scratch. > When Lisp was born, Stephen Wolfram was still wearing diapers. > > For your information: Mathematica was my first Lisp-like language. I > used it about 10 years almost every day and I love it because of the > beauty of the concept. But Mathematica has two serious problems: first, > there is only one implementation and it is commercial, and secondly, > Mathematica is very, very slowly and does not generate executable code > that can be used without Mathematica itself. Thus, comparisons to other > languages, such as Lisp are not fair. you are right... thought these aspects don't have much to do with function naming. i tend to think that Mathematica is that way due to a unique mind, Stephen Wolfram. And if i may say, i share much mindset with him with respect to many lang design issues. (or rather, Mathematica was my first lang for about 6 years too) But i think rather, Mathematica's lang design philosophy more has to do with certain pure mathematician mindset. This is somewhat similar to how haskell is a lang designed such that it is much independent of any concept of hardware. Same here with Mathematica, but on the naming aspect, Mathematica's function names is designed without even much relation to comp sci lingoes, but rather, the essense of ideas captured in a mathematical way. Xah ∑ http://xahlee.org/ ☄ -- http://mail.python.org/mailman/listinfo/python-list
Re: how to name a function in a comp lang (design)
Am 20.10.2010 14:07, schrieb Xah Lee: On Oct 20, 4:52 am, Marc Mientki wrote: Am 20.10.2010 13:14, schrieb Xah Lee: See also: • 〈The Importance of Terminology's Quality In Computer Languages〉 http://xahlee.org/UnixResource_dir/writ/naming_functions.html where i gave some examples of the naming. "I'd like to introduce a blog post by Stephen Wolfram, on the design process of Mathematica. In particular, he touches on the importance of naming of functions." "The functions in Mathematica, are usually very well-named, in contrast to most other computing languages." "Let me give a few example. [...]" thanks for your post. didn' t know you also use Mathematica. Not anymore, unfortunately. New job = no Mathematica. I tried with Maxima, but it is considered syntactically Middle Ages. Terribly confused (vectors, arrays, matrix, lists, sets - maxima does not know the motto of "list for everything"). It is much easier to improve something good than to invent from scratch. When Lisp was born, Stephen Wolfram was still wearing diapers. For your information: Mathematica was my first Lisp-like language. I used it about 10 years almost every day and I love it because of the beauty of the concept. But Mathematica has two serious problems: first, there is only one implementation and it is commercial, and secondly, Mathematica is very, very slowly and does not generate executable code that can be used without Mathematica itself. Thus, comparisons to other languages, such as Lisp are not fair. you are right... thought these aspects don't have much to do with function naming. Yes. I have it written because I see that you like to call Mathematica as a counter-example, in many cases. i tend to think that Mathematica is that way due to a unique mind, Stephen Wolfram. And if i may say, i share much mindset with him with respect to many lang design issues. Yes, me too, alone but for performance reasons, Mathematica in the area where I work (image processing) is not suitable. I mean - not research or rapid prototyping, but industrial image processing. (or rather, Mathematica was my first lang for about 6 years too) Mathematica = first language at all? No FORTRAN/BASIC/Pascal/C? regards Marc -- http://mail.python.org/mailman/listinfo/python-list
Re: Python3: Is this a bug in urllib?
On Oct 20, 12:47 am, Johannes Bauer wrote:
>
> >>> from urllib import request; request.URLopener().open("http://google.de";)
>
aren't you supposed to call read on the return value of open?
i.e.,
request.URLopener().open("http://google.de";).read()
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Re: Unicode questions
Tobiah wrote:
> I've been reading about the Unicode today.
> I'm only vaguely understanding what it is
> and how it works.
>
> Please correct my understanding where it is lacking.
> Unicode is really just a database of character information
> such as the name, unicode section, possible
> numeric value etc. These points of information
> are indexed by standard, never changing numeric
> indexes, so that 0x2CF might point to some
> character information set, that all the world
> can agree on. The actual image that gets
> displayed in response to the integer is generally
> assigned and agreed upon, but it is up to the
> software responding to the unicode value to define
> and generate the actual image that will represent that
> character.
Correct. The "actual images" are called glyphs in Unicode-speak.
> Now for the mysterious encodings. There is the UTF-{8,16,32}
> which only seem to indicate what the binary representation
> of the unicode character points is going to be. Then there
> are 100 or so other encoding, many of which are language
> specific. ASCII encoding happens to be a 1-1 mapping up
> to 127, but then there are others for various languages etc.
> I was thinking maybe this special case and the others were lookup
> mappings, where a
> particular language user could work with characters perhaps
> in the range of 0-255 like we do for ASCII, but then when
> decoding, to share with others, the plain unicode representation
> would be shared? Why can't we just say "unicode is unicode"
> and just share files the way ASCII users do. Just have a huge
> ASCII style table that everyone sticks to. Please enlighten
> my vague and probably ill-formed conception of this whole thing.
UTF-n are transfer encodings of the Unicode table (the one you
are probably referring to). They represent the same code points,
but using different trade-offs.
If you're looking for a short intro to Unicode in Python,
have a look at these talks I've given on the subject:
http://www.egenix.com/library/presentations/#PythonAndUnicode
http://www.egenix.com/library/presentations/#DesigningUnicodeAwareApplicationsInPython
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eGenix.com
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exception during module initialization + python3
Has behavior of exception thrown during module initialization changed with python3? using boost::python, throwing a c++ exception in module initialization, I get: SystemError: initialization of ldpc_45 raised unreported exception I exepected to see the string associated with exception, which gave useful information (file not found, in this case). I believe under python2.6 this would have happened (but I could be mistaken) -- http://mail.python.org/mailman/listinfo/python-list
Re: overriding a property
On 19 Okt, 16:07, Benjamin Peterson wrote: > Lucasm gmail.com> writes: > > > I would like to override the property for an instance of A to say the > > string 'bla'. > > A.return_five = "blah" I guess you did not test that. :) -- http://mail.python.org/mailman/listinfo/python-list
Re: overriding a property
On 19 Okt, 18:28, Steven D'Aprano wrote: > On Tue, 19 Oct 2010 06:39:56 -0700, Lucasm wrote: > > Hi, > > > A question. Is it possible to dynamically override a property? > > > class A(object): > > @property > > def return_five(self): > > return 5 > > > I would like to override the property for an instance of A to say the > > string 'bla'. > >>> class A(object): > > ... _five = 5 # class attribute shared by all instances > ... @property > ... def return_five(self): > ... return self._five > ... > > >>> a = A() > >>> a._five = 'bla' # set an instance attribute > >>> b = A() > >>> print a.return_five > bla > >>> print b.return_five > > 5 > > -- > Steven Thanks for the answers. I would like to override the property though without making special modifications in the main class beforehand. Is this possible? -- http://mail.python.org/mailman/listinfo/python-list
Re: annoying CL echo in interactive python / ipython
In Jed Smith writes: >On Tue, Oct 19, 2010 at 2:35 PM, kj wrote: >> In Jed Smith smith.org> writes: >> >>>On Tue, Oct 19, 2010 at 1:37 PM, kj wrote: >> % stty -echo >> >>>That doesn't do what you think it does. >> >> Gee, thanks. =A0That really helped. =A0I'll go talk to my guru now, >> and meditate over this. >You're right, I could have been more clear. I was nudging you to go >read the man page of stty(1), but since you won't and want to get >snarky instead, I will for you: >> echo (-echo) >> Echo back (do not echo back) every character typed. I read that, and it did not add anything new to what I already knew about stty -echo. >I'm going to guess that the percent sign in your prompt indicates that >you're using zsh(1). With my minimally-customized zsh, the echo >option is reset every time the prompt is displayed. That means you can >type "stty -echo", push CR, the echo option is cleared, then zsh >immediately sets it before you get to type again. Wrong guess. After I run "stty -echo", the echoing stays disabled: % stty -echo % date Wed Oct 20 10:01:46 EDT 2010 % date Wed Oct 20 10:01:47 EDT 2010 % date Wed Oct 20 10:01:48 EDT 2010 % date Wed Oct 20 10:01:49 EDT 2010 As to the guess about readline, I only observe this problem with python (interactive) and ipython, but not with, say, the Perl debugger, which uses readline as well. FWIW. ~kj -- http://mail.python.org/mailman/listinfo/python-list
Re: overriding a property
Lucasm wrote: > On 19 Okt, 18:28, Steven D'Aprano cybersource.com.au> wrote: >> On Tue, 19 Oct 2010 06:39:56 -0700, Lucasm wrote: >> > Hi, >> >> > A question. Is it possible to dynamically override a property? >> >> > class A(object): >> > @property >> > def return_five(self): >> > return 5 >> >> > I would like to override the property for an instance of A to say the >> > string 'bla'. >> >>> class A(object): >> >> ... _five = 5 # class attribute shared by all instances >> ... @property >> ... def return_five(self): >> ... return self._five >> ... >> >> >>> a = A() >> >>> a._five = 'bla' # set an instance attribute >> >>> b = A() >> >>> print a.return_five >> bla >> >>> print b.return_five >> >> 5 >> >> -- >> Steven > > Thanks for the answers. I would like to override the property though > without making special modifications in the main class beforehand. Is > this possible? You can dynamically change the instance's class: >>> class A(object): ... @property ... def five(self): return 5 ... >>> a = A() >>> b = A() >>> class B(type(b)): ... @property ... def five(self): return "FIVE" ... >>> b.__class__ = B >>> a.five 5 >>> b.five 'FIVE' But still -- what you are trying looks like a bad idea. What's your usecase? Peter -- http://mail.python.org/mailman/listinfo/python-list
Re: overriding a property
On 20 Okt, 16:09, Peter Otten <__pete...@web.de> wrote: > Lucasm wrote: > > On 19 Okt, 18:28, Steven D'Aprano > cybersource.com.au> wrote: > >> On Tue, 19 Oct 2010 06:39:56 -0700, Lucasm wrote: > >> > Hi, > > >> > A question. Is it possible to dynamically override a property? > > >> > class A(object): > >> > @property > >> > def return_five(self): > >> > return 5 > > >> > I would like to override the property for an instance of A to say the > >> > string 'bla'. > >> >>> class A(object): > > >> ... _five = 5 # class attribute shared by all instances > >> ... @property > >> ... def return_five(self): > >> ... return self._five > >> ... > > >> >>> a = A() > >> >>> a._five = 'bla' # set an instance attribute > >> >>> b = A() > >> >>> print a.return_five > >> bla > >> >>> print b.return_five > > >> 5 > > >> -- > >> Steven > > > Thanks for the answers. I would like to override the property though > > without making special modifications in the main class beforehand. Is > > this possible? > > You can dynamically change the instance's class: > > >>> class A(object): > > ... @property > ... def five(self): return 5 > ...>>> a = A() > >>> b = A() > >>> class B(type(b)): > > ... @property > ... def five(self): return "FIVE" > ...>>> b.__class__ = B > >>> a.five > 5 > >>> b.five > > 'FIVE' > > But still -- what you are trying looks like a bad idea. What's your usecase? > > Peter Thanks for your answer. That's exactly the thing I'm doing right now and it works :) My use case is testing. I want to test a class and reduce the complexity of the output generated by certain properties. It would be nice to know alternatives to this approach. -- http://mail.python.org/mailman/listinfo/python-list
Re: overriding a property
On 10/20/2010 9:59 AM, Lucasm wrote: Thanks for the answers. I would like to override the property though without making special modifications in the main class beforehand. Is this possible? Take a look at http://docs.python.org/reference/datamodel.html#descriptors The last paragraph of Section 3.4.2.3. Invoking Descriptors says: The property() function is implemented as a data descriptor. Accordingly, instances cannot override the behavior of a property. -John -- http://mail.python.org/mailman/listinfo/python-list
Re: Print to an IPP printer (pkipplib?)
On Fri, 15 Oct 2010 15:28:10 -0400, Adam Tauno Williams wrote: > I've found the module pkipplib which seems to work well for things like > interrogating an IPP (CUPS) server. But is there a way to send a print > job to an IPP print queue? [and no, the local system knows nothing about > the print architecture so popenlp is not an option]. I just want to > send the data from a file handle to a remote IPP queue as a print job. See RFC 2910. -- martin@ | Martin Gregorie gregorie. | Essex, UK org | -- http://mail.python.org/mailman/listinfo/python-list
Tkinter (and IDLE) window "docking?" effect when dragging root window to edge of display
Python 2.6/2.7 (32-bit) for Windows: When I drag a Tkinter root window to the left, upper, or right edge of my display ... as soon as my mouse cursor hits the visible edge of the display ... as if I'm trying to dock the window on the edge in question ... a giant phantom Tkinter window pops up underneath my window showing the size and placement of my root window if I would release my mouse button. You can see the identical behavior if you drag a non-maxmized IDLE window to one of your screen edges (left, top, bottom). This behavior seems to be "by design". I'm looking for a way to either disable this "docking" functionality or trap the "docking" event and size and position my root window according to custom needs. I've been googling this question and I can't seem to find the right terms to describe the event that is being raised or the behavior that I'm observing. Any ideas? Malcolm -- http://mail.python.org/mailman/listinfo/python-list
Re: overriding a property
Lucasm writes: > Thanks for the answers. I would like to override the property though > without making special modifications in the main class beforehand. Is > this possible? That will not be easy. When you access obj.return_five, python looks up 'return_five' in type(obj) to see what the return_five property even means. (See http://users.rcn.com/python/download/Descriptor.htm for details of how this works.) Since you can't change the source of A, you are left with two options: you can monkey-patch A.return_five to make it optionally consult the instance, or you can assign to instance's __class__ to make it point to a subclass of A that implements a different 'return_five'. Both options are fairly unpleasant, but I think I'd go with the first one. Others have spelled out the __class__-changing variant. While monkey-patching is not the cleanest of practices to adopt, in my mind it still beats assigning to __class__. Here is an example: # Wrap return_five so it supports per-instance customization, but # without copy-pasting the original. def wrap_return_five(orig): @property def wrapper(self): if 'return_five' in self.__dict__: return self.__dict__['return_five'] return orig.__get__(self, type(self)) return wrapper >>> A.return_five = wrap_return_five(A.return_five) >>> a = A() >>> b = A() >>> a.return_five 5 >>> a.__dict__['return_five'] = 10 >>> a.return_five 10 >>> b.return_five 5 If you want, you can make a.return_five itself settable, but I'll leave that as an excercise for the reader. -- http://mail.python.org/mailman/listinfo/python-list
Re: Reading Outlook .msg file using Python
On Oct 20, 1:41 am, Tim Golden wrote: > On 19/10/2010 22:48, John Henry wrote: > > > Looks like this flag is valid only if you are getting messages > > directly from Outlook. When reading the msg file, the flag is > > invalid. > > > Same issue when accessing attachments. In addition, the MAPITable > > method does not seem to work at all when trying to get attachments out > > of the msg file (works when dealing with message in an Outlook > > mailbox). Eitherway, the display_name doesn't work when trying to > > display the filename of the attachment. > > > I was able to get the date by using the PR_TRANSPORT_MESSAGE_HEADERS > > mapitags > > Ah, thanks. As you will have realised, my code is basically geared > to reading an Outlook/Exchange message box. I hadn't really tried > it on individual message files, except my original excerpt. If it > were opportune, I'd be interested in seeing your working code. > > TJG When (and if) I finally figure out how to get it done, I surely will make the code available. It's pretty close. All I need is to figure out how to extract the attachments. Too bad I don't know (and don't have) C#. This guy did it so cleanly: http://www.codeproject.com/KB/office/reading_an_outlook_msg.aspx?msg=3639675#xx3639675xx May be somebody that knows both C# and Python can convert the code (not much code) and then the Python community will have it. As it stands, it seems the solution is available in Java, C#, VB but not Python. -- http://mail.python.org/mailman/listinfo/python-list
python shell silently ignores termios.tcsetattr()
This post is a continuation of an earlier thread called annoying CL echo in interactive python / ipython I found some more clues to the problem, although no solution yet. First, I found a post from 2009.05.09 that describes exactly the same situation I've observed (although it got no responses): http://groups.google.com/group/comp.emacs/browse_thread/thread/72973892717d0bfa I tried to fix the problem by applying the equivalent of "stty -echo" within a python interactive session, but discovered that this setting is immediately (and silently) overwritten. The following interaction illustrates what I mean. (I've added my comments, preceded by ###.) First I start the barest possible instance of Emacs (only the bare mininum of environment settings, and loading no configurations from an ~/.emacs file): % env -i HOME=$HOME DISPLAY=$DISPLAY TERM=$TERM /opt/local/bin/emacs -Q Within Emacs, the first command I execute is M-x shell, to bring up an Emacs shell. What follows is the interaction within this shell: sh-3.2$ stty -a ### first I get the initial settings for the terminal speed 9600 baud; 0 rows; 0 columns; lflags: icanon isig iexten -echo echoe -echok echoke -echonl echoctl -echoprt -altwerase -noflsh -tostop -flusho -pendin -nokerninfo -extproc iflags: -istrip icrnl -inlcr -igncr ixon -ixoff ixany imaxbel -iutf8 -ignbrk brkint -inpck -ignpar -parmrk oflags: opost -onlcr -oxtabs -onocr -onlret cflags: cread cs8 -parenb -parodd hupcl -clocal -cstopb -crtscts -dsrflow -dtrflow -mdmbuf cchars: discard = ^O; dsusp = ^Y; eof = ^D; eol = ; eol2 = ; erase = ; intr = ^C; kill = ; lnext = ^V; min = 1; quit = ^\; reprint = ^R; start = ^Q; status = ^T; stop = ^S; susp = ^Z; time = 0; werase = ^W; ### note the echo setting under lflags and the onlcr setting under ### oflags; also note that the stty -a command above was not echoed sh-3.2$ python ### next I start an interactive python session Python 2.6.1 (r261:67515, Feb 11 2010, 00:51:29) [GCC 4.2.1 (Apple Inc. build 5646)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import termios import termios ### note the echoing >>> old = termios.tcgetattr(1) old = termios.tcgetattr(1) >>> new = termios.tcgetattr(1) new = termios.tcgetattr(1) >>> new[3] = new[3] & ~termios.ECHO & ~termios.ONLCR new[3] = new[3] & ~termios.ECHO >>> old[3], new[3] old[3], new[3] (536872395, 536872385) >>> (termios.tcsetattr(1, termios.TCSANOW, new), termios.tcgetattr(1)[3], >>> old[3], new[3]) (termios.tcsetattr(1, termios.TCSANOW, new), termios.tcgetattr(1)[3], old[3], new[3]) (None, 536872385, 536872395, 536872385) ### The output above shows that the setting attempted through ### tcsetattr "took" momentarily... >>> termios.tcgetattr(1) == old termios.tcgetattr(1) == old True ### ...but by this point it has already been reset back to its original value. >>> termios.tcgetattr(1)[3], old[3], new[3] termios.tcgetattr(1)[3], old[3], new[3] (536872395, 536872395, 536872385) >>> ^D sh-3.2$ stty -a ### after quitting python, the echo and onlcr settings have been reversed stty -a speed 9600 baud; 0 rows; 0 columns; lflags: icanon isig iexten echo echoe -echok echoke -echonl echoctl -echoprt -altwerase -noflsh -tostop -flusho -pendin -nokerninfo -extproc iflags: -istrip icrnl -inlcr -igncr ixon -ixoff ixany imaxbel -iutf8 -ignbrk brkint -inpck -ignpar -parmrk oflags: opost onlcr -oxtabs -onocr -onlret cflags: cread cs8 -parenb -parodd hupcl -clocal -cstopb -crtscts -dsrflow -dtrflow -mdmbuf cchars: discard = ^O; dsusp = ^Y; eof = ^D; eol = ; eol2 = ; erase = ^?; intr = ^C; kill = ^U; lnext = ^V; min = 1; quit = ^\; reprint = ^R; start = ^Q; status = ^T; stop = ^S; susp = ^Z; time = 0; werase = ^W; sh-3.2$ Does anyone understand what's going on? Is there any way to prevent python from resetting the settings made with tcgetattr? (I realize that this is relatively low-level stuff, so it is unlikely that there's a clean solution; I'm hoping, however, that there may be a way to fool python into doing the right thing; after all, this strange behavior only happens under the Emacs shell; I don't observe it under, e.g., Terminal or xterm.) TIA! ~kj -- http://mail.python.org/mailman/listinfo/python-list
Re: Reading Outlook .msg file using Python
On Oct 20, 9:01 am, John Henry wrote:
> On Oct 20, 1:41 am, Tim Golden wrote:
>
>
>
> > On 19/10/2010 22:48, John Henry wrote:
>
> > > Looks like this flag is valid only if you are getting messages
> > > directly from Outlook. When reading the msg file, the flag is
> > > invalid.
>
> > > Same issue when accessing attachments. In addition, the MAPITable
> > > method does not seem to work at all when trying to get attachments out
> > > of the msg file (works when dealing with message in an Outlook
> > > mailbox). Eitherway, the display_name doesn't work when trying to
> > > display the filename of the attachment.
>
> > > I was able to get the date by using the PR_TRANSPORT_MESSAGE_HEADERS
> > > mapitags
>
> > Ah, thanks. As you will have realised, my code is basically geared
> > to reading an Outlook/Exchange message box. I hadn't really tried
> > it on individual message files, except my original excerpt. If it
> > were opportune, I'd be interested in seeing your working code.
>
> > TJG
>
> When (and if) I finally figure out how to get it done, I surely will
> make the code available. It's pretty close. All I need is to figure
> out how to extract the attachments.
>
> Too bad I don't know (and don't have) C#. This guy did it so cleanly:
>
> http://www.codeproject.com/KB/office/reading_an_outlook_msg.aspx?msg=...
>
> May be somebody that knows both C# and Python can convert the code
> (not much code) and then the Python community will have it. As it
> stands, it seems the solution is available in Java, C#, VB but
> not Python.
BTW: For the benefit of future search on this topic, with the code
listed above where:
storage_flags = STGM_DIRECT | STGM_READ | STGM_SHARE_EXCLUSIVE
I had to change it to:
storage_flags = STGM_DIRECT | STGM_READ | STGM_SHARE_DENY_NONE |
STGM_TRANSACTED
otherwise I get a sharing violation (see
http://efreedom.com/Question/1-1086814/Opening-OLE-Compound-Documents-Read-StgOpenStorage).
For now, I am using a brute force method (http://mail.python.org/
pipermail/python-win32/2009-February/008825.html) to get the names of
the attachments and if I need to extract the attachments, I pop up the
message in Outlook and let Outlook extract the files. Ugly but fits
my client's need for now. Hopefully there will be a cleaner solution
down the road.
Here's my code for brute forcing attachments out of the msg file (very
ugly):
def get_attachments(self, fileID):
#from win32com.storagecon import *
from win32com import storagecon
import pythoncom
flags = storagecon.STGM_READ | storagecon.STGM_SHARE_DENY_NONE |
storagecon.STGM_TRANSACTED
try:
storage = pythoncom.StgOpenStorage (fileID, None, flags)
except:
return []
flags = storagecon.STGM_READ | storagecon.STGM_SHARE_EXCLUSIVE
attachments=[]
for data in storage.EnumElements ():
print data[0], data[1]
if data[1] == 2 or data[0] == "__substg1.0_007D001F":
stream = storage.OpenStream (data[0], None,
flags)
try:
msg = stream.Read (data[2])
except:
pass
else:
msg = repr (msg).replace("\
\x00","").strip("'").replace("%23","#")
if data[0] == "__substg1.0_007D001F":
try:
attachments.append(msg.split("name=\"")[1].split("\"")[0])
except:
pass
return attachments
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Unix-head needs to Windows-ize his Python script
I have a handy Python script, which takes a few command-line arguments, and accepts a few options. I developed it on Unix, with very much of a Unix-mindset. Some Windows-using colleagues have asked me to make the script "easy to use under Windows 7". I.e.: no command-line. Therefore, I want to adapt my script, with the minimum amount of work, so that it can have a double-clickable icon that brings up a small GUI to accept command-line options (including a couple of file-selectors for input and output files). I am Windows-illiterate, so I really would like to keep this as barebones as possible. Where should I look to learn more about how to do this? Thx! --G (P.S. in case it matters, it's OK to assume that Python will be installed on the Windows system; IOW, the script need not bring with it a Python interpreter and libraries.) -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter (and IDLE) window "docking?" effect when dragging root window to edge of display
On Wed, Oct 20, 2010 at 11:32 AM, wrote: > Python 2.6/2.7 (32-bit) for Windows: When I drag a Tkinter root window to > the left, upper, or right edge of my display ... as soon as my mouse cursor > hits the visible edge of the display ... as if I'm trying to dock the window > on the edge in question ... a giant phantom Tkinter window pops up > underneath my window showing the size and placement of my root window if I > would release my mouse button. > > You can see the identical behavior if you drag a non-maxmized IDLE window to > one of your screen edges (left, top, bottom). This behavior seems to be "by > design". > > I'm looking for a way to either disable this "docking" functionality or trap > the "docking" event and size and position my root window according to custom > needs. I've been googling this question and I can't seem to find the right > terms to describe the event that is being raised or the behavior that I'm > observing. It sounds like you are describing the "Aero Snap" feature in Windows 7. If you want to turn it off system wide, you can do that in the control panel: Open the Ease of Access control panel Click Make it easier to focus on tasks Check "Prevent windows from being automatically arranged when moved to the edge of the screen" I'm afraid I don't have any Tk experience to contribute, but this Stack Overflow thread may be slightly helpful, even though it's talking about trying to do this in .NET, and there aren't really any conclusions reached. http://stackoverflow.com/questions/2470685/disable-aero-snap-wpf At a guess the windows message triggering the resize would be a WM_SIZE. You may be able to override how your application responds to those messages to dock the way you want to. It'll probably take some experimentation, though. -- Jerry -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script
Write a small GUI in the easy-to-use and cross-platform wxPython module. All this GUI needs to do is allow them to input the arguments. The code can then import your stand-alone version of the script and execute its code, passing the arguments in. wxPython is just Python. -- http://mail.python.org/mailman/listinfo/python-list
Re: pylint -- should I just ignore it sometimes?
On 2010-10-20, Jean-Michel Pichavant wrote: > except ValueError, e: > Use meaningful names, this is so important. It's important, but meaning can come from idiom, not from the word used. > 'e' is not meaningful. Sure it is. It's like i for a loop index. There's a reason mathematicians use x, not the_value_that_can_vary. > When dealing with such issue like "I'm too lazy to > write proper engligh" always think that what is the most important thing > is to save the Reader's time, not the Writer's time. Using 'e' would > force to reader to introspect to code to get an idea of what 'e' is. If the reader can't track a single-letter idiomatic name over two consecutive lines of code, I don't think I can save the reader time. The reader is beyond my ability to help at that point. Furthermore, long names take longer to read and process. As a *reader*, I vastly prefer: except foo, e: print "Fatal error:", e to anything you could do with a longer name. Consider, admittedly a C example: for (int i = 0; i < n; ++i) a[i] += 1; vs: for (int index_into_array = 0; index_into_array < size_of_array; ++index_into_array) array_into_which_we_are_indexing[index_into_array] += 1; Here's the thing. The issue is not that I'm too lazy to write English. The issue is that English, like every other language, USES PRONOUNS. Because pronouns are a good way to MASSIVELY streamline communication. It's not just a convenience to the writer/speaker; it also makes life easier for the reader/listener. Short variable names are pronouns. They make sense when you'd use a pronoun in English. "If we catch a KeyError, we print an error message including it." We'd use a pronoun. Makes sense to use a short variable name. > Moreover, code completion makes use of long names costless. No, it doesn't. It preserves their higher cognitive load in parsing. Dogmatism about rejecting short variable names is inconsistent with the psychology of human readers. Compilers don't care about length of variable names. Humans do, and there are times when they benefit more from a short and recognizeable name than they do from a long and "expressive" one. -s -- Copyright 2010, all wrongs reversed. Peter Seebach / usenet-nos...@seebs.net http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated! I am not speaking for my employer, although they do rent some of my opinions. -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script
On 2010-10-20, Shawn Milochik wrote: > Write a small GUI in the easy-to-use and cross-platform wxPython > module. All this GUI needs to do is allow them to input the > arguments. The code can then import your stand-alone version of the > script and execute its code, passing the arguments in. > wxPython is just Python. No, it's not. You can't assume that any windows machine with Python installed also has wxPython installed. The only GUI kit that you can come close to "assuming" is Tkinter. -- Grant Edwards grant.b.edwardsYow! !! I am having fun!!! at gmail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Tkinter (and IDLE) window "docking?" effect when dragging root window to edge of display
Jerry, > It sounds like you are describing the "Aero Snap" feature in Windows 7. Bingo! You hit the nail and the head. Thank you very much! Regards, Malcolm -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script
On Oct 20, 2010, at 2:00 PM, Grant Edwards wrote: > On 2010-10-20, Shawn Milochik wrote: > ript and execute its code, passing the arguments in. > >> wxPython is just Python. > > No, it's not. > > You can't assume that any windows machine with Python installed also > has wxPython installed. The only GUI kit that you can come close to > "assuming" is Tkinter. > I didn't mean to imply that wxPython is in the standard library. Just that you write Python code when you create a wxPython app. I apologize for the lack of clarity. I recommended wxPython instead of Tkinter because of the opinions I've heard from other Python developers who prefer the former (I've never used Tkinter). Also, wxPython automatically looks native Mac, Windows, and Linux. Shawn -- http://mail.python.org/mailman/listinfo/python-list
Re: Classes in a class: how to access variables from one in another
On 18 Oct 2010 22:29:27 GMT Steven D'Aprano wrote: > On Mon, 18 Oct 2010 09:34:07 -0700, Chris Rebert wrote: > > > Also, Python's scoping rules, particularly for class-level scopes, > > don't work the way programmers from languages where nested classes > > are common would expect: > [snip example] > > > I'm sorry, I don't see that "language Foo programmers will be > surprised that Python is not language Foo" is an argument against > Python programmers using nested classes. Surely it's an argument > against writing Foo in Python? > > > Alright, alright, you made your point. You should go into politics. ;) /W -- To reach me via email, replace INVALID with the country code of my home country. But if you spam me, I'll be one sour Kraut. -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script
On 2010-10-20, Shawn Milochik wrote: > > On Oct 20, 2010, at 2:00 PM, Grant Edwards wrote: > >> On 2010-10-20, Shawn Milochik wrote: >> ript and execute its code, passing the arguments in. >> >>> wxPython is just Python. >> >> No, it's not. >> >> You can't assume that any windows machine with Python installed also >> has wxPython installed. The only GUI kit that you can come close to >> "assuming" is Tkinter. > > I didn't mean to imply that wxPython is in the standard library. Just > that you write Python code when you create a wxPython app. Ah, I see. While that is true, the same statement can be made for all of the GUI toolkits: PyQT, PyGTK, wxPython, pyFltk, etc. When creating a Python application using a GUI toolkit with a Python binding, all you have to do is write Python. > I recommended wxPython instead of Tkinter because of the opinions > I've heard from other Python developers who prefer the former (I've > never used Tkinter). Also, wxPython automatically looks native Mac, > Windows, and Linux. That's sort of true, but you've got to bundle the application correctly on Windows to make it happen (it didn't "just work" the last time I tried it). The OP didn't seem interested in bundling his app. I find Tkinter is much easier to use that wxPython for simple applications, but I generally switch to wxPython for anything more complex that a single top-level window with a handful of widgets in it. I also find the Tkinter API to be far more stable than wxWindows. I've one slightly complex Tkinter application that I wrote 10 years ago whose UI code is still running unchanged on brand new installs. The main advantage of Tkinter is that it's the "standard" GUI library for Python, and you can usually depend on it being installed on a Windows machine if Python is installed. It's included in both the "standard" Windows installer and the ActiveState windows installer. None of the other toolkits are. If, like the OP, you don't want to bundle up your application with a copy of Python and GUI libraries, Tkinter is pretty much your only option. -- Grant Edwards grant.b.edwardsYow! Am I accompanied by a at PARENT or GUARDIAN? gmail.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Script to capture stderr of subprocess
On Tue, 19 Oct 2010 11:21:49 -0700, jslow...@gmail.com wrote:
> Actually, if it was possible, it would be nice to capture all
> the bytes going between stdin and stdout in a file as well for
> debugging purposes.
If the child process expects to be running on a terminal, you would need
to use a pseudo-terminal (pty). See the "pty" module (although the
documentation assumes that you already understand how Unix ptys work).
Redirecting stdin/stdout to pipes tends to interfere with interactive
behaviour for a whole variety of reasons. Not least of which being that
many programs specifically use something like isatty(fileno(stdin)) to
determine whether they are being run interactively.
> cmd = ['/usr/local/bin/runcobol'] + sys.argv[1:]
> proc = subprocess.Popen(cmd, stderr=subprocess.PIPE)
> proc.communicate()
>
> if proc.returncode:
> f = file('/tmp/boom.txt', 'w')
> f.write(" ".join(cmd) + " returned unexpectedly.\n")
> f.write(proc.stderr.read(-1))
> f.close()
> sys.exit(proc.returncode)
The .communicate() method waits for the process to terminate. Once that
has happened, you can't call .read() on proc.stderr.
The .communicate method returns a tuple, where the first item is whatever
was written to stdout (provided that stdout was redirected to a pipe), and
the second item is whatever was written to stderr (provided that stderr
was redirected to a pipe).
So you should use e.g.:
errors = proc.communicate()[1]
--
http://mail.python.org/mailman/listinfo/python-list
Re: pylint -- should I just ignore it sometimes?
On Wed, 20 Oct 2010 12:47:02 +0200, Jean-Michel Pichavant wrote: > except ValueError, e: > > Use meaningful names, this is so important. 'e' is not meaningful. > 'exception' would be slighly better. While I agree with everything else you had to say, I have to take exception to this comment [pun intended]. "e" as a short name for a generic exception instance is perfectly reasonable, like: i, j, k for an index, or a loop variable e.g. for i in range(100) n for some other integer variable s for a string x for a float, or an arbitrary sequence object e.g. [x.spam() for x in some_sequence] and similar. The last example is very instructive. What do you gain by racking your brain for a "more meaningful" name instead of x? The obvious alternatives, "obj" or "item", are equally generic as "x", they don't add any further information. And how much information do you need? It's easy to parody: [some_sequence_item.spam() for some_sequence_item in some_sequence] The very shortness of the name is valuable because it reduces the *human* parsing time in reading, and there is no cost because the conventions are so familiar. The convention of "for i in ..." says "this is a loop over an integer" so strongly, that I would argue that "for index in ..." would actually *delay* comprehension. Furthermore, the use of a single letter cues the reader that this variable isn't notable -- there's nothing unusual or unconventional about it, or it isn't the important part of the algorithm, or that its scope is severely limited. For instance, consider the classic example of exchanging two variables in Python: a, b = b, a versus: thing, other_thing = other_thing, thing The first example puts the emphasis on the *technique*, not the variables. The second obscures it behind needlessly longer but still generic names. You are absolutely right to insist on meaningful variable names. Where you go wrong is to assume that single letter names can't be meaningful. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
socket.sendto / UDP problem
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
Hello,
When transmitting via UDP to a PLC, I run into a strange problem
where socket.sendto returns double the number of characters sent in the
datagram. I thought this was an error and used Wireshark to sniff the
connection and discovered that it did, in fact, include two copies of
the string I am transmitting in the same packet. The only
thing differentiating this string from prior commands is its length.
The functional ones are between 5 & 7 bytes (with 16 byte responses
received successfully) but transmitting a 66-byte message actually
results in 132 bytes being sent!
I am running 2.6.6 on Windows XP, which I understand has a default
minimum buffersize of 576 bytes which I would think is sufficient.
Apologies if this is somewhat incoherent, I'm cross-eyed from staring
at this!
- - Todd
- -- code --
def PLC_Functions(command, argument):
"""
Command is one of: GetTray, Status, SetText
Argument is one of: tray number (as string), None, message (as string)
The PC transmits and receives on socket 2260 (pcSocket)
The PLC transmits and receives on socket 2002
The protocol used is UDP
"""
MegaMatPLC =
(config.get('megamat','plcip'),int(config.get('megamat','targetport')))
# at some point it will be necessary to wrap these in TRY/EXCEPT to handle
the socket errors
# create UDP socket
pcSocket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM,
socket.IPPROTO_UDP)
# bind it
pcSocket.bind((config.get('megamat','pcip'),int(config.get('megamat','sourceport'
# make them blocking (i/o is 'fire-and-forget' to a PLC that may or may not
respond in a given time.)
# non-blocking fails and raises windows exceptions for some reason
(20-Oct-2010)
pcSocket.setblocking(True)
if command == 'CallTray':
# frame 1 (see docs for frame sequence)
print 'Received call tray command for tray %s' %(argument)
getReadyMsg = '0145\r'
totalsent = 0
while totalsent < len(getReadyMsg):
sent = pcSocket.sendto(getReadyMsg[totalsent:],MegaMatPLC)
if sent == 0:
raise RunTimeError('Transmission failure. Please confirm
MegaMat settings in megapy.ini')
totalsent = totalsent + sent
# Frame 2
response = ''
while response.find('\r') < 0:
response = pcSocket.recv(17)
if response == '':
raise RunTimeError('PLC did not respond')
#this should be changed. The MIF software will wait until it
receives a response or timeout, not ABEND
print response
if response[0:4] == '0135':
print 'Drive ready received.'
#Frame 3
getReadyMsg2 = '016040\r'
totalsent = 0
while totalsent < len(getReadyMsg2):
sent = pcSocket.sendto(getReadyMsg2[totalsent:],MegaMatPLC)
if sent == 0:
raise RunTimeError('Transmission failure. Please confirm
MegaMat settings in megapy.ini')
totalsent = totalsent + sent
# Frame 4
response = ''
while response.find('\r') < 0:
response = pcSocket.recv(16)
if response == '':
raise RunTimeError('PLC did not respond')
#this should be changed. The MIF software will wait until
it receives a response or timeout, not ABEND
print response
if response[0:4] == '0130':
# Frame 5
# Transmit tray request
if int(argument) < 10:
shelfPrefix = ''
else:
shelfPrefix = '000'
shelf = shelfPrefix + argument
unit = '001'
stack = '01'
"""
There is a 10 digit number plus 40 blanks spaces after the
shelf description built above.
It is possible this is for storing shelf descriptions and
barcodes on the PLC. We will
follow the example of the MIF software and put a phony b/c and
blank description.
X is a field terminator and \r is the end of transmission
(EoT.)
"""
fakeBarcode = '1234567890'
fortySpacesField = ' '*40 + 'X\r'
getShelfMsg = '0105' + shelf + unit + stack + fakeBarcode +
fortySpacesField
print 'Transmitting shelf request as follows: \n' + getShelfMsg
print 'Get shelf length %i' % (len(getShelfMsg))
totalsent = 0
while totalsent < len(getShelfMsg):
sent = pcSocket.sendto(getShelfMsg[totalsent:],MegaMatPLC)
print sent, totalsent, len(getShelfMsg)
if sent == 0:
raise Run
Re: Unix-head needs to Windows-ize his Python script
On 2010-10-20, Grant Edwards wrote: > On 2010-10-20, Shawn Milochik wrote: > >> Write a small GUI in the easy-to-use and cross-platform wxPython >> module. All this GUI needs to do is allow them to input the >> arguments. The code can then import your stand-alone version of the >> script and execute its code, passing the arguments in. > >> wxPython is just Python. > > No, it's not. > > You can't assume that any windows machine with Python installed also > has wxPython installed. The only GUI kit that you can come close to > "assuming" is Tkinter. If using other toolkits, it's possible to compile a distributable package with dependencies using py2exe. That way even Python need not be installed. http://www.py2exe.org/ UTK -- http://mail.python.org/mailman/listinfo/python-list
Re: Unix-head needs to Windows-ize his Python script
On 2010-10-20, Urpo T. Koira wrote: > On 2010-10-20, Grant Edwards wrote: >> On 2010-10-20, Shawn Milochik wrote: >> >>> Write a small GUI in the easy-to-use and cross-platform wxPython >>> module. All this GUI needs to do is allow them to input the >>> arguments. The code can then import your stand-alone version of the >>> script and execute its code, passing the arguments in. >> >>> wxPython is just Python. >> >> No, it's not. >> >> You can't assume that any windows machine with Python installed also >> has wxPython installed. The only GUI kit that you can come close to >> "assuming" is Tkinter. > > If using other toolkits, it's possible to compile a distributable > package with dependencies using py2exe. That way even Python need not > be installed. > > http://www.py2exe.org/ But, the OP said that he could assume that Python was already installed, that he was windows-illiterate, and that he wanted to keep things as bare-bones as possible. I've used wxWindows+py2exe in the past, and it can be made to work well. But, compared to distributing a simple source file for a Tkinter program, wxWindows+py2exe is _far_ from "bare-bones", and not something to be casually undertaken by the windows-illiterate. -- Grant Edwards grant.b.edwardsYow! I'm pretending I'm at pulling in a TROUT! Am I gmail.comdoing it correctly?? -- http://mail.python.org/mailman/listinfo/python-list
Re: pylint -- should I just ignore it sometimes?
Another situation in which I needed to disable such kind of warnings is while working with graphics modules. I often use variable names such as x, y, z for coordinates, or r,g,b for colors. Would longer names make the reader's life easier? Best regards, Matteo On Wed, Oct 20, 2010 at 9:37 PM, Steven D'Aprano wrote: > On Wed, 20 Oct 2010 12:47:02 +0200, Jean-Michel Pichavant wrote: > >> except ValueError, e: >> >> Use meaningful names, this is so important. 'e' is not meaningful. >> 'exception' would be slighly better. > > While I agree with everything else you had to say, I have to take > exception to this comment [pun intended]. > > "e" as a short name for a generic exception instance is perfectly > reasonable, like: > > i, j, k for an index, or a loop variable > e.g. for i in range(100) > n for some other integer variable > s for a string > x for a float, or an arbitrary sequence object > e.g. [x.spam() for x in some_sequence] > > and similar. > > The last example is very instructive. What do you gain by racking your > brain for a "more meaningful" name instead of x? The obvious > alternatives, "obj" or "item", are equally generic as "x", they don't add > any further information. And how much information do you need? It's easy > to parody: > > [some_sequence_item.spam() for some_sequence_item in some_sequence] > > The very shortness of the name is valuable because it reduces the *human* > parsing time in reading, and there is no cost because the conventions are > so familiar. The convention of "for i in ..." says "this is a loop over > an integer" so strongly, that I would argue that "for index in ..." would > actually *delay* comprehension. > > Furthermore, the use of a single letter cues the reader that this > variable isn't notable -- there's nothing unusual or unconventional about > it, or it isn't the important part of the algorithm, or that its scope is > severely limited. For instance, consider the classic example of > exchanging two variables in Python: > > a, b = b, a > > versus: > > thing, other_thing = other_thing, thing > > The first example puts the emphasis on the *technique*, not the > variables. The second obscures it behind needlessly longer but still > generic names. > > You are absolutely right to insist on meaningful variable names. Where > you go wrong is to assume that single letter names can't be meaningful. > > > > -- > Steven > -- > http://mail.python.org/mailman/listinfo/python-list > -- Matteo Landi http://www.matteolandi.net/ -- http://mail.python.org/mailman/listinfo/python-list
logging: StreamHandler’s newline terminator now co nfigurable
When StreamHandler writes a formatted log message to its stream, it adds a newline terminator. This behaviour is inherited by FileHandler and the other classes which derive from it (such as the rotating file handlers). For most people, that’s what they want, since they get log messages on separate lines without having to explicitly code newlines in their log messages. However, some people want the flexibility to not have this newline automatically appended to logged messages. Starting with Python 3.2, the message terminator will be configurable. This has been done by adding a terminator attribute to StreamHandler, which when emitting an event now writes the formatted message to its stream first, and then writes the terminator. If you don’t want newline termination for a handler, just set the handler instance’s terminator attribute to the empty string. There’s a small chance that this approach will cause unexpected behaviour – in the unlikely instance that someone is setting a terminator attribute on an a StreamHandler or one of its subclasses for their own, unrelated purposes. Other than that, the new behaviour should be backwards compatible. If this change is likely to adversely affect you for any reason, please let me know, by replying to this post. The change has already been checked into the py3k branch, and you are welcome to try it out. Regards, Vinay Sajip -- http://mail.python.org/mailman/listinfo/python-list
Re: pylint -- should I just ignore it sometimes?
On 2010-10-20, Matteo Landi wrote: > Another situation in which I needed to disable such kind of warnings > is while working with graphics modules. > I often use variable names such as x, y, z for coordinates, or r,g,b for > colors. > Would longer names make the reader's life easier? Interesting point. Which is really easier to read: x, y, z = p.nextpoint() xCoordinate, yCoordinate, zCoordinate = polygon.nextPointCoordinates() -s -- Copyright 2010, all wrongs reversed. Peter Seebach / usenet-nos...@seebs.net http://www.seebs.net/log/ <-- lawsuits, religion, and funny pictures http://en.wikipedia.org/wiki/Fair_Game_(Scientology) <-- get educated! I am not speaking for my employer, although they do rent some of my opinions. -- http://mail.python.org/mailman/listinfo/python-list
Re: exception during module initialization + python3
Neal Becker wrote: > Has behavior of exception thrown during module initialization changed with > python3? > > using boost::python, throwing a c++ exception in module initialization, I > get: > > SystemError: initialization of ldpc_45 raised unreported exception > > I exepected to see the string associated with exception, which gave useful > information (file not found, in this case). > > I believe under python2.6 this would have happened (but I could be > mistaken) I just tried it, and I'm not mistaken. On python2.6 I get my nice error message, but on python3.1.2 I just get the above SystemError: initialization of ldpc_45 raised unreported exception -- http://mail.python.org/mailman/listinfo/python-list
Re: merge list of tuples with list
Many thanks for all these suggestions! here is a short proof that you guys are absolutely right and my solution is pretty inefficient. One of your ways: $ python /[long_path]/timeit.py 'a=[(1,2,3),(4,5,6)];b=(7,8);[x+(y,) for x,y in zip(a,b)]' 100 loops, best of 3: 1.44 usec per loop And my way: $ python /[long_path]/timeit.py 'a=[(1,2,3), (4,5,6)];b=[7,8];map(tuple, map(lambda x: x + [b.pop(0)] , map(list, a)))' 10 loops, best of 3: 5.33 usec per loop I really appreciate your solutions but they bring me to a new question: Why is my solution so inefficient? The same operation without the list/tuple conversion $ python /[long_path]/timeit.py 'a=[[1,2,3], [4,5,6]];b=[7,8];map(lambda x: x + [b.pop(0)] , a)' 10 loops, best of 3: 3.36 usec per loop is still horrible slow. Could anybody explain me what it makes so slow? Is it the map() function or maybe the lambda construct? Greetings, Daniel -- http://mail.python.org/mailman/listinfo/python-list
Data files with distutils and special paths
Hi!
I was following the documentation about distutils [1] in order to install my
application in a python-way. But installing it in /usr/local (following the
official doc [2] too) with
$ sudo python setup.py install --prefix=/usr/local
The data files are created inside the python package, in
/usr/local/lib/python2.6/dist-packages... The structure is very similar at
the given in [1]:
setup.py
foo/__init.py__
foo(gui.py
foo/core.py
foo/data/gui/main.glade
foo/data/images/logo.png
And the setup.py:
from setuptools import setup
files = ['data/gui/*.glade', 'data/icons/*.png']
setup(name='foo',
version='1.0',
author='John Doe',
author_email='john@example.com',
packages=['foo'],
dpackage_dir={'foo': 'foo'},
package_data={'foo': files}, )
What I'm missing?
Regards,
[1]
http://docs.python.org/distutils/setupscript.html#installing-package-data
[2]
http://docs.python.org/install/#alternate-installation-unix-the-prefix-scheme
--
Pablo Recio Quijano
Desarrollador Django
Yaco Sistemas - http://www.yaco.es/
--
http://mail.python.org/mailman/listinfo/python-list
Re: pylint -- should I just ignore it sometimes?
Seebs writes: > Interesting point. Which is really easier to read: > > x, y, z = p.nextpoint() > > xCoordinate, yCoordinate, zCoordinate = polygon.nextPointCoordinates() The latter uses camelCase, so it's horrible right out of the gate :-) -- \ “The cost of education is trivial compared to the cost of | `\ ignorance.” —Thomas Jefferson | _o__) | Ben Finney -- http://mail.python.org/mailman/listinfo/python-list
python-imaging-sane
I'm trying to get my application to scan, create a .pdf, and then save
it in a patient's folder. I found python-imaging-sane but I can't get
things to work correctly. Here is what's happening at the command
prompt:
import sane
sane.init()
(16777235, 1, 0, 19)
print sane.get_devices()
[('canondr:libusb:001:002', 'Canon', 'P-150', 'sheetfed scanner')]
s = sane.open(sane.get_devices()[0][0])
s.start()
i = s.snap()
Traceback (most recent call last):
File "", line 1, in
File "/usr/lib/python2.6/dist-packages/sane.py", line 243, in snap
self.dev.snap( im.im.id, no_cancel )
_sane.error: Operation was cancelled
Ultimately I would like to get it to scan duplex and do multipage
docs. Thanks for any help.
Mike Barron
--
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Re: Unix-head needs to Windows-ize his Python script
On Oct 20, 11:38 am, gb345 wrote: > I have a handy Python script, which takes a few command-line > arguments, and accepts a few options. I developed it on Unix, with > very much of a Unix-mindset. Some Windows-using colleagues have > asked me to make the script "easy to use under Windows 7". I.e.: > no command-line. > > Therefore, I want to adapt my script, with the minimum amount of > work, so that it can have a double-clickable icon that brings up > a small GUI to accept command-line options (including a couple of > file-selectors for input and output files). > > I am Windows-illiterate, so I really would like to keep this as > barebones as possible. Where should I look to learn more about > how to do this? > > Thx! > > --G > > (P.S. in case it matters, it's OK to assume that Python will be > installed on the Windows system; IOW, the script need not bring > with it a Python interpreter and libraries.) Teach them "Windows key" -> Run -> cmd or very useful "Open Command Window Here" right click option. http://www.downloadsquad.com/2009/02/09/windows-7-tip-elevated-command-prompt-anywhere/ Failing that you may try EasyDialogs http://www.doughellmann.com/PyMOTW/EasyDialogs/index.html The build in module is Mac only. The Windows version is available here. http://www.averdevelopment.com/python/EasyDialogs.html Waldemar -- http://mail.python.org/mailman/listinfo/python-list
Re: socket.sendto / UDP problem
On 20/10/2010 21:20, Todd Walter wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Hello, When transmitting via UDP to a PLC, I run into a strange problem where socket.sendto returns double the number of characters sent in the datagram. I thought this was an error and used Wireshark to sniff the connection and discovered that it did, in fact, include two copies of the string I am transmitting in the same packet. The only thing differentiating this string from prior commands is its length. The functional ones are between 5& 7 bytes (with 16 byte responses received successfully) but transmitting a 66-byte message actually results in 132 bytes being sent! I am running 2.6.6 on Windows XP, which I understand has a default minimum buffersize of 576 bytes which I would think is sufficient. Apologies if this is somewhat incoherent, I'm cross-eyed from staring at this! [snip] The docs for 'sendto' say: """The socket should not be connected to a remote socket, since the destination socket is specified by address.""" Could your problem be caused by you binding the socket to a source port, so it's going out both to the bound port _and_ the one given the binding? Have you tried using two sockets, one outgoing and the other incoming? BTW, your code for handling the response doesn't cope with it coming in a bit at a time. It loops discard any previous data from the previous iteration. Also, it's more Pythonic to say: while '\r' not in response: ... -- http://mail.python.org/mailman/listinfo/python-list
Re: merge list of tuples with list
On Wed, 20 Oct 2010 14:32:53 -0700, Daniel Wagner wrote: > I really appreciate your solutions but they bring me to a new question: > Why is my solution so inefficient? The same operation without the > list/tuple conversion > > $ python /[long_path]/timeit.py 'a=[[1,2,3], [4,5,6]];b=[7,8];map(lambda > x: x + [b.pop(0)] , a)' 10 loops, best of 3: 3.36 usec per loop > > is still horrible slow. What makes you say that? 3 microseconds to create four lists, two assignments, create a function object, then inside the map look up the global b twice, the method 'pop' twice, call the method twice, resize the list b twice, create an inner list twice, concatenate that list with another list twice, and stuff those two new lists into a new list... 3usec for all that in Python code doesn't seem unreasonable to me. On my PC, it's two orders of magnitude slower than a pass statement. That sounds about right to me. $ python -m timeit 1000 loops, best of 3: 0.0325 usec per loop $ python -m timeit 'a=[[1,2,3], [4,5,6]];b=[7,8];map(lambda x: x + [b.pop (0)] , a)' 10 loops, best of 3: 4.32 usec per loop Can we do better? $ python -m timeit -s 'a=[[1,2,3], [4,5,6]]; f = lambda x: x + [b.pop (0)]' 'b=[7,8]; map(f, a)' 10 loops, best of 3: 3.25 usec per loop On my system, moving the creation of the list a and the code being timed and into the setup code reduces the time by 25%. Not too shabby. > Could anybody explain me what it makes so slow? > Is it the map() function or maybe the lambda construct? lambdas are just functions -- there is no speed difference between a function def add(a, b): return a+b and lambda a, b: a+b The looping overhead of map(f, data) is minimal. But in this case, the function you're calling does a fair bit of work: lambda x: x + [b.pop(0)] This has to lookup the global b, resize it, create a new list, concatenate it with the list x (which creates a new list, not an in-place concatenation) and return that. The amount of work is non-trivial, and I don't think that 3us is unreasonable. But for large lists b, it will become slow, because resizing the list is slow. Popping from the start on a regular list has to move every element over, one by one. You may find using collections.deque will be *much* faster for large lists. (But probably not for small lists.) Personally, the approach I'd take is: a = [[1,2,3], [4,5,6]] b = [7,8] [x+[y] for x,y in zip(a,b)] Speedwise: $ python -m timeit -s 'a=[[1,2,3], [4,5,6]]; b=[7,8]' '[x+[y] for x,y in zip(a,b)]' 10 loops, best of 3: 2.43 usec per loop If anyone can do better than that (modulo hardware differences), I'd be surprised. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
Re: Python3: Is this a bug in urllib?
On Oct 20, 8:32 pm, Justin Ezequiel
wrote:
> On Oct 20, 12:47 am, Johannes Bauer wrote:
>
>
>
> > >>> from urllib import request; request.URLopener().open("http://google.de";)
>
> aren't you supposed to call read on the return value of open?
> i.e.,
> .read()
better yet,
f = request.URLopener().open("http://google.de";)
f.read()
f.close()
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Re: merge list of tuples with list
> [b.pop(0)] > > This has to lookup the global b, resize it, create a new list, > concatenate it with the list x (which creates a new list, not an in-place > concatenation) and return that. The amount of work is non-trivial, and I > don't think that 3us is unreasonable. > I forgot to take account for the resizing of the list b. Now it makes sense. Thanks! > Personally, the approach I'd take is: > > a = [[1,2,3], [4,5,6]] > b = [7,8] > [x+[y] for x,y in zip(a,b)] > > > Speedwise: > > $ python -m timeit -s 'a=[[1,2,3], [4,5,6]]; b=[7,8]' '[x+[y] for x,y in > zip(a,b)]' > 10 loops, best of 3: 2.43 usec per loop > > > If anyone can do better than that (modulo hardware differences), I'd be > surprised. > Yeah, this seems to be a nice solution. Greetings, Daniel -- http://mail.python.org/mailman/listinfo/python-list
Re: python shell silently ignores termios.tcsetattr()
In message , kj wrote: > I tried to fix the problem by applying the equivalent of "stty > -echo" within a python interactive session, but discovered that > this setting is immediately (and silently) overwritten. That seems reasonable behaviour; the command loop is resetting the terminal to a reasonable state to allow it to read the next command. But the command you execute can do anything it likes in-between. What’s wrong with that? -- http://mail.python.org/mailman/listinfo/python-list
Filename for stdout
If my python script is called with stdout (or stdin or stderr) redirected to a file, how can I find the filename under Linux? Under Windows? Thanks, RG -- http://mail.python.org/mailman/listinfo/python-list
Re: Filename for stdout
On Thu, Oct 21, 2010 at 6:17 AM, Richard Gibbs wrote: > If my python script is called with stdout (or stdin or stderr) redirected to > a file, how can I find the filename under Linux? Under Windows? I don't believe there is a way to do this. The shell normally takes care of pipes. When you do: $ ./foo > /tmp/foobar You're telling your shell to write the stdout output of foo to the file /tmp/foobar sys.stdout won't actually tell you anything useful. It's normally just a file descriptor. cheers James -- -- James Mills -- -- "Problems are solved by method" -- http://mail.python.org/mailman/listinfo/python-list
Re: Filename for stdout
On 2010-10-21, James Mills wrote:
> On Thu, Oct 21, 2010 at 6:17 AM, Richard Gibbs
> wrote:
>> If my python script is called with stdout (or stdin or stderr) redirected to
>> a file, how can I find the filename under Linux??? Under Windows?
>
> I don't believe there is a way to do this.
There is, but it's not pretty.
> The shell normally takes care of pipes.
And it takes care of redirects. Which, importantly for this case, are
not the same thing.
> When you do:
>
> $ ./foo > /tmp/foobar
>
> You're telling your shell to write the stdout output of foo to the
> file /tmp/foobar
Not quite. You're telling the shell to attach the file /tmp/foobar to
stdout before running the program foo. If the shell was reading data
from foo's stdout and then writing it to /tmp/foobar, we'd be out of
luck. But that's not what a redirect does.
> sys.stdout won't actually tell you anything useful. It's normally
> just a file descriptor.
Ah, but file descriptors _can_ tell you something useful. :)
The program below will print the filename(s) (if there are any) when
stdout is a regular file. NB: to make it easy to test, it only
searches below ".", so you'd probably want to widen the search if
you're doing this in a real program. [Asking sys.stdout for its
fileno is a bit redundant since it's defined to be 1 in the Unix
world.]
[I've no clue how to do this under Windows.]
[I also don't know what the answer is to the question the OP should
have asked. But, I suspect this is a case of asking for a method to
implement the wrong solution to an unstated problem.]
In any case, here's how do do "the wrong thing":
#!/usr/bin/python
import sys,os,stat
write = sys.stderr.write
# search for file(s) with given device/inode values
def findFile(dev,ino):
namelist = []
for root,dirs,files in os.walk("."):
for name in files:
path = os.path.join(root,name)
statinfo = os.stat(path)
fdev,fino = statinfo[stat.ST_DEV],statinfo[stat.ST_INO]
if (dev,ino) == (fdev,fino):
namelist.append(path)
return namelist
# get stat info of stdout, and if it's a regular file, search
# filesystem under '.' for matching file(s)
fd = sys.stdout.fileno()
statinfo = os.fstat(fd)
mode = statinfo[stat.ST_MODE]
if stat.S_ISCHR(mode):
write("stdout is a char device\n")
elif stat.S_ISREG(mode):
dev,ino = statinfo[stat.ST_DEV],statinfo[stat.ST_INO]
write("stdout is a regular file on device %d inode %d\n" % (dev,ino))
write("filename(s): %s\n" % findFile(dev,ino))
elif stat.S_ISSOCK(mode):
write("stdout is a socket\n")
elif stat.S_ISFIFO(mode):
write("stdout is a FIFO\n")
else:
write("stdout unknown type\n")
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how to scrutch a dict()
Not Hyp:
def _scrunch(**dict):
result = {}
for key, value in dict.items():
if value is not None: result[key] = value
return result
That says "throw away every item in a dict if the Value is None".
Are there any tighter or smarmier ways to do that? Python does so
often manage maps better than that...
--
Phlip
http://zeekland.zeroplayer.com/
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Re: how to scrutch a dict()
Phlip writes:
> def _scrunch(**dict):
> result = {}
>
> for key, value in dict.items():
> if value is not None: result[key] = value
>
> return result
>
> That says "throw away every item in a dict if the Value is None".
> Are there any tighter or smarmier ways to do that? Python does so
> often manage maps better than that...
Untested:
def _scrunch(**kwargs):
return dict(k,v for k,v in kwargs.iteritems() if v is not None)
Note: it's best not to use "dict" as a parameter name, since it is a
built in function (dictionary constructor). It's also a bit of a code
smell that you're using keyword args like that.
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Re: how to scrutch a dict()
On Thu, Oct 21, 2010 at 2:32 PM, Phlip wrote:
> Not Hyp:
>
> def _scrunch(**dict):
> result = {}
>
> for key, value in dict.items():
> if value is not None: result[key] = value
>
> return result
>
> That says "throw away every item in a dict if the Value is None".
>
> Are there any tighter or smarmier ways to do that? Python does so
> often manage maps better than that...
Rather than creating a new dict why don't you just do:
def _scrunch(d):
for k, v in d.items():
if v is None:
del d[k]
cheers
James
--
-- James Mills
--
-- "Problems are solved by method"
--
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Re: how to scrutch a dict()
On Wed, Oct 20, 2010 at 9:40 PM, Paul Rubin wrote:
> Phlip writes:
>> def _scrunch(**dict):
>> result = {}
>>
>> for key, value in dict.items():
>> if value is not None: result[key] = value
>>
>> return result
>>
>> That says "throw away every item in a dict if the Value is None".
>> Are there any tighter or smarmier ways to do that? Python does so
>> often manage maps better than that...
>
> Untested:
>
> def _scrunch(**kwargs):
> return dict(k,v for k,v in kwargs.iteritems() if v is not None)
Also, in Python 3, one can instead use a dict comprehension (see PEP
274: http://www.python.org/dev/peps/pep-0274/ ), which makes this a
bit more elegant:
result = {k:v for k,v in kwargs.items() if v is not None}
Cheers,
Chris
--
"Smarmy" code; now there's an interesting concept.
http://blog.rebertia.com
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Re: how to scrutch a dict()
Phlip writes:
> Not Hyp:
I don't know what this means; I hope it's not important.
> def _scrunch(**dict):
You're clobbering the built-in ‘dict’ binding here.
You're also requiring the input to be keyword parameters. Why not simply
take a single parameter, and allow the *caller* to decide if they want
to split up the key-value pairs?
> result = {}
>
> for key, value in dict.items():
> if value is not None: result[key] = value
>
> return result
>
> That says "throw away every item in a dict if the Value is None".
>
> Are there any tighter or smarmier ways to do that?
I'm not sure “smarmy” means what you think it means; you might be amused
to read a dictionary definition for that word.
As for your code, it seems simple enough as is. You could translate it
to a generator expression and feed that to the ‘dict’ constructor::
out_dict = dict(
(key value) for (key, value) in in_dict.items()
if value is not None)
but that loses the utility of having it all wrapped up in a function,
which would be my preference::
def scrunchdict(in_dict):
out_dict = dict(
(key value) for (key, value) in in_dict.items()
if value is not None)
return out_dict
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\“Some people, when confronted with a problem, think ‘I know, |
`\ I'll use regular expressions’. Now they have two problems.” |
_o__) —Jamie Zawinski, in alt.religion.emacs |
Ben Finney
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