Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
Remarks heard & form updated. Nathaniel, I'm not sure about that: even if the code is 2- and 3-compatible you'll pick one runtime. 2 others questions now mention writing polyglot code. By the way I published the survey on HN, /r/programming & /r/python: https://news.ycombinator.com/item?id=8730156 http://redd.it/2ovlwm http://redd.it/2ovls4 Feel free to publish it anywhere else, to get as many answers as possible. Bruno 2014-12-10 18:24 GMT+01:00 Nathaniel Smith : > On 10 Dec 2014 17:16, "Ian Cordasco" wrote: > > > > On Wed, Dec 10, 2014 at 11:10 AM, Donald Stufft > wrote: > > > > > > On Dec 10, 2014, at 11:59 AM, Bruno Cauet > wrote: > > > > > > Hi all, > > > Last year a survey was conducted on python 2 and 3 usage. > > > Here is the 2014 edition, slightly updated (from 9 to 11 questions). > > > It should not take you more than 1 minute to fill. I would be pleased > if you > > > took that time. > > > > > > Here's the url: http://goo.gl/forms/tDTcm8UzB3 > > > I'll publish the results around the end of the year. > > > > > > Last year results: https://wiki.python.org/moin/2.x-vs-3.x-survey > > > > > > > > > Just going to say http://d.stufft.io/image/0z1841112o0C is a hard > question > > > to answer, since most code I write is both. > > > > > > > The same holds for me. > > That question appears to have just grown a "compatible with both" option. > > It might make sense to add a similar option to the following question > about what you use for personal projects. > > -n > > ___ > Python-Dev mailing list > python-...@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/brunocauet%40gmail.com > > -- https://mail.python.org/mailman/listinfo/python-list
Python 2.x and 3.x use survey, 2014 edition
Hi all, Last year a survey was conducted on python 2 and 3 usage. Here is the 2014 edition, slightly updated (from 9 to 11 questions). It should not take you more than 1 minute to fill. I would be pleased if you took that time. Here's the url: http://goo.gl/forms/tDTcm8UzB3 I'll publish the results around the end of the year. Last year results: https://wiki.python.org/moin/2.x-vs-3.x-survey Thank you Bruno -- https://mail.python.org/mailman/listinfo/python-list
Re: How to detect that a function argument is the default one
- Original Message - > From: "Chris Angelico" > > c1 = Circle((0,0), 10, None) > > print c1.mass > > 20 > > c1.radius = 20 > > print c1.mass > > 40 > > I think that juust might count as scope creep :) > ChrisA Here you go :p c1 = Circle((0,0), 10, None) print c1.mass 20 c1.grow(+10) print c1.mass 40 JM -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. -- https://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
I hesitated a while before deciding not to include it! Apart from python core development what would be the reasons to work mostly on this version ? I'll fix the omission right ahead. — Tagada tsouin tsouin On Wed, Dec 10, 2014 at 10:57 PM, Chris Angelico wrote: > On Thu, Dec 11, 2014 at 3:59 AM, Bruno Cauet wrote: >> Here's the url: http://goo.gl/forms/tDTcm8UzB3 >> I'll publish the results around the end of the year. > On "Which versions do you use?", 3.5 is not included. My primary > Python 3 build on here is a 3.5 built from trunk. :) > ChrisA > -- > https://mail.python.org/mailman/listinfo/python-list-- https://mail.python.org/mailman/listinfo/python-list
ANN: eGenix mxODBC Plone/Zope Database Adapter 2.2.0
ANNOUNCING mxODBC Plone/Zope Database Adapter Version 2.2.0 for the Plone CMS and Zope server platform Available for Plone 4.0-4.3 and Plone 5.0, Zope 2.12 and 2.13, on Windows, Linux, Mac OS X, FreeBSD and other platforms This announcement is also available on our web-site for online reading: http://www.egenix.com/company/news/eGenix-mxODBC-Zope-DA-2.2.0-GA.html INTRODUCTION The eGenix mxODBC Zope DA allows you to easily connect your Zope or Plone CMS installation to just about any database backend on the market today, giving you the reliability of the commercially supported eGenix product mxODBC and the flexibility of the ODBC standard as middle-tier architecture. The mxODBC Zope Database Adapter is highly portable, just like Zope itself and provides a high performance interface to all your ODBC data sources, using a single well-supported interface on Windows, Linux, Mac OS X, FreeBSD and other platforms. This makes it ideal for deployment in ZEO Clusters and Zope hosting environments where stability and high performance are a top priority, establishing an excellent basis and scalable solution for your Plone CMS. Product page: http://www.egenix.com/products/zope/mxODBCZopeDA/ NEWS We are pleased to announce our new version 2.2.0 of the mxODBC Zope/Plone Database Adapter product. In this release, we have upgraded the adapter to mxODBC 3.3.1 and added compatibility with the latest Plone releases and ODBC drivers/managers. Feature Enhancements * Compatible with Plone 4.0 - 4.3. * Compatible with the upcoming Plone 5.0. Enhanced Support for Stored Procedures * Added documentation on how to call stored procedures from Plone / Zope. * Added support for input, output and input/output parameters to the .callproc() method for calling stored procedures. * Added documentation on how to use External Methods to access and use the mxODBC Zope DA connection objects. Fast Cursor Types * Switched to forward-only cursor types for all database backends, since this provides a much better performance for MS SQL Server and IBM DB2 drivers. Updated mxODBC API * Access all new features from the updated mxODBC 3.3 API via the DatabaseConnect.connection attribute or by importing the mxODBC API directly. Please see the mxODBC 3.3.0 and 3.3.1 release announcements for full details. Easier Installation * ThreadLock egg distribution provided by eGenix to avoid having a compiler installed for the installation buildout run. Please see our ThreadLock distribution release announcement for details: http://www.egenix.com/company/news/eGenix-ThreadLock-Distribution-2.13.0.1.html For the full list of features, please see the mxODBC Zope DA feature list: http://www.egenix.com/products/zope/mxODBCZopeDA/#Features Driver Compatibility Enhancements - * ODBC driver compatibility updated. By upgrading to the latest mxODBC 3.3 release, we are bringing all compatibility enhancements added to mxODBC 3.3 to the mxODBC Zope DA. This includes updated support for Oracle, MS SQL Server, Sybase ASE, IBM DB2, PostgreSQL and MySQL. See the mxODBC 3.3.0 and 3.3.1 release announcements for full details: http://www.egenix.com/company/news/eGenix-mxODBC-3.3.0-GA.html http://www.egenix.com/company/news/eGenix-mxODBC-3.3.1-GA.html * ODBC manager compatibility updated. Built against unixODBC 2.3.2, iODBC 3.52.8, DataDirect 7.1.2 on Unix. Built against the MS Windows Manager ODBC on Windows. Built against iODBC 3.52.8 on Mac OS X. The complete list of changes is available on the mxODBC Zope DA changelog page. http://www.egenix.com/products/zope/mxODBCZopeDA/changelog.html UPGRADING Users are encouraged to upgrade to this latest mxODBC Plone/Zope Database Adapter release to benefit from the new features and updated ODBC driver support. We have taken special care not to introduce backwards incompatible changes, making the upgrade experience as smooth as possible. For major and minor upgrade purchases, we will give out 20% discount coupons going from mxODBC Zope DA 1.x to 2.2 and 50% coupons for upgrades from mxODBC 2.x to 2.2. After upgrade, use of the original license from which you upgraded is no longer permitted. Patch level upgrades (e.g. 2.2.0 to 2.2.1) are always free of charge. Please contact the eGenix.com Sales Team with your existing license serials for details for an upgrade discount coupon. If you want to try the new release before purchase, you can request 30-day evaluation licenses by v
Re: Python script isn't producing text in data file
On Thu, 11 Dec 2014 05:19:44 +, Grant Edwards wrote: > On 2014-12-11, Docfxit wrote: > >> I am happy to paste it into a post. The reason I didn't is because >> it's very large. The Python script is 1239 lines long. The example >> summary is 105 lines long. The input log is 6810 lines long. >> >> Are you sure you want me to post all of that here? Or would you like >> me to post it on a pastebin? > > You're going to need to create a _short_ example program that > demonstrates the problem you're asking about. It needs to be included > in your post and fit in _one_ screen full. A few people will look at > longer examples, but your chances of the right person seeing it and > figuring out your problem before their internal timer (or the one on the > microwave) goes "ding!" drop precipitously as it gets longer. Your > chances approach 0 pretty fast if it requires following a URL to some > site full of malware[1]. > > > [1] Yes, all sites are full of malware. Also creating the shorter example will often reveal the subtle bug or design flaw that you are currently overlooking. this is a good start towards diagnosing your own issue (& then of course people here will help if you are still having the problem) -- You're too beautiful to ignore. Too much woman. -- Kirk to Yeoman Rand, "The Enemy Within", stardate unknown -- https://mail.python.org/mailman/listinfo/python-list
Re: Python script isn't producing text in data file
On Wed, 10 Dec 2014 20:23:56 -0800, Docfxit wrote: > On Wednesday, December 10, 2014 7:55:17 PM UTC-8, Ben Finney wrote: >> Docfxit writes: >> >> > I am happy to paste it into a post. The reason I didn't is because >> > it's very large. The Python script is 1239 lines long. >> >> That's too long to direct us toward, no matter where you put it. >> >> Your task, then, is to construct a *much* smaller and simpler example >> that still demonstrates the behaviour you want explained. >> >> Once you have that, one of two things will be true: >> >> * It will be small and clear enough that we can discuss it here >> usefully. Or >> >> * You will have understood the problem well enough to solve it >> yourself. >> >> Please, construct a Short, Self-Contained, Complete Example >> http://sscce.org/> of code that exhibits the behaviour. >> >> -- >> \ "When cryptography is outlawed, bayl bhgynjf jvyy unir >> | >> `\ cevinpl." --Anonymous >> | >> _o__) >> | >> Ben Finney > > Thank you all for the encouragement to make it smaller. > I don't know enough about Python to figure out how to isolate where the > problem is happening. That should then be your first port of call, check the Python documentation & step through the code manually. > > Maybe it would be best If I could get some help in getting a debugger > working so I can try to work through the script one line at a time. it is probably just as easy to add print statements into a copy of the code so you can where the code has got to & what your Values are. > I have started to install a debugger but I can't get it working. > I'm working in Win7 Pro. I'm trying to get Winpdb working. > I have an error when I run the debugger. It says winpdb is missing. > > winpdb.py is located in: -same version > C:\Python27\Lib\site-packages C:\winpdb-winpdb > > winpdb is located in: > C:\winpdb-winpdb > > Is winpdb supposed to be in c:\python27? > > If it is, how is it supposed to get there? (Some install?) > > Thanks, > > Docfxit -- You canna change the laws of physics, Captain; I've got to have thirty minutes! -- https://mail.python.org/mailman/listinfo/python-list
Re: Python script isn't producing text in data file
Docfxit wrote: > I don't know enough about Python to figure out how to isolate where the > problem is happening. Can you get hold of the person who wrote the script? -- https://mail.python.org/mailman/listinfo/python-list
Re: How to detect that a function argument is the default one
- Original Message - > From: "ast" > > > >> Note : what is the mass of a circle ? > > > > In fact it's a ball moving in a plan. > I will change that name. I would advise to remove the the mass parameter of your Sphere initialization. It could be inconsistent with the radius. To compute the mass you would need the radius and the volumetric mass density. pseudo code: class Sphere(object): def __init__(self, center, radius, density): @property def volume(self): return 4/3.*pi*self.radius^3 @property def mass(self): return self.volume*self.density You'll find no the net the density for most of the materials. JM -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. -- https://mail.python.org/mailman/listinfo/python-list
Problem with a dialog
Hello I provide two almost identical small test case programs. The first one works as expected, 'True' is printed on the console. With the second one Python complains that 'test' is not known. I dont understand why. Python 3.4, windows # ## First # from tkinter import * import tkinter.simpledialog class MyDialog(tkinter.simpledialog.Dialog): def body(self, master): print(test) def apply(self): pass root = Tk() test = True setup = MyDialog(root) # 'True' is printed on the console. Works ! # ## Second # from tkinter import * import tkinter.simpledialog class MyDialog(tkinter.simpledialog.Dialog): def body(self, master): print(test) def apply(self): pass def try_(): test = True setup = MyDialog(root) root = Tk() try_() # NameError: name 'test' is not defined -- https://mail.python.org/mailman/listinfo/python-list
Re: gdb python print truncated string
-=Scorp=- Okay, i fixed this limit (truncated) as follows: find python2.7-gdb.py (in /usr/lib... path) and found/change value for MAX_OUTPUT_LEN const (default value is 1024), then restart gdb and you'll se new truncate limits. -- https://mail.python.org/mailman/listinfo/python-list
Re: Problem with a dialog
ast wrote: > Hello > > I provide two almost identical small test case programs. > The first one works as expected, 'True' is printed on the > console. > With the second one Python complains that 'test' is not > known. I dont understand why. > # > ## Second > # > > from tkinter import * > import tkinter.simpledialog > > class MyDialog(tkinter.simpledialog.Dialog): > > def body(self, master): > print(test) Here, "test" must be a global variable. Since the body() method doesn't assign to the name "test" (e.g. a line like "test = 23") that makes it a global. > def apply(self): > pass > > def try_(): > test = True > setup = MyDialog(root) Here, the try_() function creates two local variables, "test" and "setup". The important thing here is that "test" is local to the function, not global. That means that when MyDialog's body() method runs, it looks for a global variable "test", but there isn't one. The local variable inside try_() is invisible to it. You can make "test" global by declaring it global: def try_(): global test test = True setup = MyDialog(root) If that solves your problem to your satisfaction, you can stop reading now. Still here? Good :-) To be a little more advanced for a moment... what you tried to do (possibly inadvertently?) is possible in some computer languages, but not Python. In most languages, the rule is that functions (and methods) can see the following variables: - variables inside the function itself (local variables) - variables inside nested functions [see below], sometimes called "nonlocal variables" - global variables defined at the top level of the module or program (outside of any function) but not variables inside functions that *call* your function. This is called "static scoping" or "lexical scoping". What's a nested function? That's just when you put a function inside another function: def outer(): x = 23 def inner(): return 3*x return inner() + 1 In this case, inner() is nested inside outer(), so it can see outer()'s local variables, such as "x". Nothing else can see inner(), since it is local to outer(). As I said, most programming languages work like this. But a small minority use a different system, called "dynamic scoping". In dynamic scoping, it doesn't matter *where* a function is defined, only where it is called. With dynamic scoping, your code would have worked correctly. If you are used to languages like Javascript, you may have done that deliberately, thinking Python worked the same way. It doesn't. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: Problem with a dialog
"Steven D'Aprano" a écrit dans le message de news:54898820$0$12989$c3e8da3$54964...@news.astraweb.com... As I said, most programming languages work like this. But a small minority use a different system, called "dynamic scoping". In dynamic scoping, it doesn't matter *where* a function is defined, only where it is called. With dynamic scoping, your code would have worked correctly. Thank you very much. This is my mistake I knew that a function defined in a scope "knows" the variables defined in that scope, at least for reading (for writing, it is more complicated). I didnt realize that my function/class was called, not defined in that scope. -- https://mail.python.org/mailman/listinfo/python-list
New member - 'odd' question
Firstly, python is one of my two current focus areas, and while I still work with python 2.7, sort of for backward compatibility, my other focus area is web development, making use of PHP, javascript, jQuery, MySQL, etc. And, I develop on windows7 64 bit machines, in conjunction with screen reader software - either jaws, or NVDA, if that means much... Now, one of the current pieces of work am busy with involves sort of automating the process of converting some MS access databases to MySQL, and manipulating/rearranging the data during the conversion process. I am implementing this using a python app, making use of wxPython to implement the GUI, and am using pyodbc to pull in the data structures, and read the data from .mdb files, and then am trying to use either pyodbc, or MySQLdb modules to then handle interaction with the MySQL side of things, and the MySQL database engine is part of the WAMP installation on my dev machine, FWIW. Now, on my primary, desktop machine, it seems like if I implement pyodbc connections and cursors to handle the input data/structures from an .mdb file, and then write out the relevant SQL queries to text files, and then try to read them in, split them into separate statements, and execute them against the MySQL database, that part of it runs fine, but, the odd issue seems to be that if I did in fact first create/open a pyodbc connection object, along with it's relevant cursor object, and even if make sure close both of them, then on my one machine, after then initiating the direct MySQLdb connection object, I am still unable to actually close the whole app down - the main class is a sort of inheritor of wx.Frame, and before closing it down, I destroy both the Frame and all it's children, but, the main oddity is that while this works fine on my other laptop, on my desktop machine it always just ends up telling me python.exe is not responding, and would I like to force it to close? And, it's definitely got something to do with the combination of having created and/or destroyed the pyodbc objects first, and then creating MySQLdb objects, since either half works fine by itself, but not together - on one machine anyway. Just wondering what can be causing this to occur on one machine, but not the other, relatively similar, but maybe cleaner machine, and how to try track down something like this? That's also why am posting this here - trying to figure out how to track down what's causing this odd behaviour. TIA Jacob Kruger Blind Biker Skype: BlindZA ...Roger Wilco wants to welcome you, to the space janitor's closet... -- https://mail.python.org/mailman/listinfo/python-list
Re: Problem with a dialog
"Steven D'Aprano" a écrit dans le message de news:54898820$0$12989$c3e8da3$54964...@news.astraweb.com... You can make "test" global by declaring it global: def try_(): global test test = True setup = MyDialog(root) If that solves your problem to your satisfaction, you can stop reading now. Since try() is a callback function called when a button is pushed, with the effect to open a dialog, I tried to define MyDialog class inside try(). The program is the following and it works. I no longer need to define test as global. Is it a good practice to define a class inside a function ? from tkinter import * import tkinter.simpledialog def try_(): class MyDialog(tkinter.simpledialog.Dialog): def body(self, master): print(test) def apply(self): pass test = True setup = MyDialog(root) root = Tk() try_() -- https://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
On Wed, Dec 10, 2014 at 5:59 PM, Bruno Cauet wrote: > Hi all, > Last year a survey was conducted on python 2 and 3 usage. > Here is the 2014 edition, slightly updated (from 9 to 11 questions). > It should not take you more than 1 minute to fill. I would be pleased if > you took that time. > > Here's the url: http://goo.gl/forms/tDTcm8UzB3 > I'll publish the results around the end of the year. > > Last year results: https://wiki.python.org/moin/2.x-vs-3.x-survey > > Thank you > Bruno > > ___ > Python-Dev mailing list > python-...@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/g.rodola%40gmail.com > I still think the only *real* obstacle remains the lack of important packages such as twisted, gevent and pika which haven't been ported yet. With those ones ported switching to Python 3 *right now* is not only possible and relatively easy, but also convenient. -- Giampaolo - http://grodola.blogspot.com -- https://mail.python.org/mailman/listinfo/python-list
Re: When do default parameters get their values set?
On Wed, Dec 10, 2014 at 7:15 PM, Steven D'Aprano
wrote:
> On Wed, 10 Dec 2014 18:18:44 -0800, Rustom Mody wrote:
>
>
> > And going the other way -- no defs only lambdas its this:
> >
> >
> f = lambda : (lambda x= {}: x)
> f()() is f()()
> > False
> d = f()
> d() is d()
> > True
>
>
> >
> > But I have a different question -- can this be demonstrated without the
> > 'is'?
>
>
> Can *what* be demonstrated? That the functions returned are different
> objects, or that the dicts are different objects? Both? Something else?
>
> Using "is" you are demonstrating that calling the function twice returns
> two distinct objects. That is the purpose of "is", to compare object
> identity. Without "is", you can compare object IDs directly:
>
> id(f()()) == id(f()())
>
> but that's ugly and less efficient. Using "is" is the more idiomatic and
> natural way to do this.
>
In CPython, that does not work, as the dictionary will be garbage collected
after each call to id:
>>> f = lambda : (lambda x= {}: x)
>>> f()() is f()()
False
>>> id(f()()) == id(f()())
True
>
> Other than that, you could do something to demonstrate the consequences
> of the two values being distinct objects:
>
> a = f()() # Call twice to get a dict.
> b = f()()
> a['key'] = 23
> b['key'] # raises KeyError
>
>
> or
>
> a = f() # Call once to get a function.
> b = f()
> a.attribute = 23
> b.attribute # raises AttributeError
>
>
> Or you could inspect the byte-code of f and try to understand it.
>
>
Another way would be to to demonstrate the behavior, without using is,
would be to use a global counter variable:
a = 1
def f():
global a
def g(b=[a]):
return b
a += 1
return g
>>> f()()
[1]
>>> f()()
[2]
>>> a = f()
>>> a()
[3]
>>> a()
[3]
>>> b = f()
>>> b()
[4]
>>> a()
[3]
--
https://mail.python.org/mailman/listinfo/python-list
is_ as method or property?
Hi, I have been looking at various places to answer this dilemma: If a class member function simply tests something and returns a b::oolean call it def is_(): pass like 'is_even'. Should I define it as a classic method def is_even(self): pass or as a property @property def is_even(self): pass The question above is based on similar question I found [1], but that one is specifically about naming. I'm trying to solve the aspect of implementation of such predicate. I've looked into the Python 3.4 libs and most of such functions is realised as a classic method, but in several cases they are defined with @property decorator, for example: email.message.MIMEPart.iis_attachment ipaddress._BaseNetwork.is_multicast ipaddress._BaseNetwork is_reserved and a few more. So, a classic method or a property, which one is the Pythonic 3 way for such member predicates? [1] *Naming Conventions* by Thorsten Kampe https://mail.python.org/pipermail/python-list/2007-June/438156.html Best regards, -- Mateusz Loskot, http://mateusz.loskot.net -- https://mail.python.org/mailman/listinfo/python-list
Re: How to detect that a function argument is the default one
On Thu, Dec 11, 2014 at 3:02 AM, Jean-Michel Pichavant < jeanmic...@sequans.com> wrote: > I would advise to remove the the mass parameter of your Sphere initialization. It could be inconsistent with the radius. > To compute the mass you would need the radius and the volumetric mass density. You assume a three-dimensional universe. Clearly this is a two-dimensional "ball" with a density equal to pi/2 mass units per area unit. -- https://mail.python.org/mailman/listinfo/python-list
Re: How to detect that a function argument is the default one
On Thu, Dec 11, 2014 at 11:03 AM, Ian Kelly wrote: > > On Thu, Dec 11, 2014 at 3:02 AM, Jean-Michel Pichavant < jeanmic...@sequans.com> wrote: > > I would advise to remove the the mass parameter of your Sphere initialization. It could be inconsistent with the radius. > > To compute the mass you would need the radius and the volumetric mass density. > > You assume a three-dimensional universe. Clearly this is a two-dimensional "ball" with a density equal to pi/2 mass units per area unit. Er. 2/pi. -- https://mail.python.org/mailman/listinfo/python-list
Re: is_ as method or property?
On Fri, Dec 12, 2014 at 4:34 AM, Mateusz Loskot wrote: > If a class member function simply tests something and > returns a b::oolean call it > > def is_(): > pass > > like 'is_even'. > > Should I define it as a classic method > > def is_even(self): > pass > > or as a property > > @property > def is_even(self): > pass A property should be used if what you're creating is "virtually an attribute". If it would make sense to have an attribute is_even, then a property is_even makes sense. If in doubt, go with a method. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: is_ as method or property?
On 12/11/2014 09:34 AM, Mateusz Loskot wrote: > > def is_(): > pass > > like 'is_even'. > > Should I define it as a classic method > > def is_even(self): > pass > > or as a property > > @property > def is_even(self): > pass > > So, a classic method or a property, which one is the Pythonic 3 way for > such member predicates? Generally, attributes (and properties look like attributes) are for items that the object already knows the answer to, and methods are for things that need to be calculated, and may change throughout the life of the object. -- ~Ethan~ signature.asc Description: OpenPGP digital signature -- https://mail.python.org/mailman/listinfo/python-list
Text Code(from 'Getting Started in Beautiful Soup' re: cd Soup , returns 'Syntax Error, invalid syntax'
At the start of Chapter 3 of 'Getting Started in Beautiful Soup' it has said to create a html file, 'ecological pyramid.html' - which I have already done re: plants 10 algae 10 deer 1000 deer 1000 rabbit 2000 fox 100 bear 100 lion 80 tiger 50 and ran it okay in 'Explorer', and text then says to save it to a folder named 'Soup' which I have done. On the next page (30) it says to navigate to that folder with the following code to the python console :- cd Soup however console rejects that code with the following return: - Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)] on win 32 Type "help", "copyright", "credits" or "license" for more information. >>> cd Soup File "", line 1 cd Soup ^ SyntaxError: invalid syntax >>> Thank you for reading, hope you can help. Yours Simon Evans -- https://mail.python.org/mailman/listinfo/python-list
Re: Text Code(from 'Getting Started in Beautiful Soup' re: cd Soup , returns 'Syntax Error, invalid syntax'
On Thursday, December 11, 2014 11:21:52 AM UTC-8, Simon Evans wrote: > At the start of Chapter 3 of 'Getting Started in Beautiful Soup' it has said > to create a html file, 'ecological > > pyramid.html' - which I have already done re: > > > > > > > > plants > 10 > > > algae > 10 > > > > > deer > 1000 > > deer > 1000 > > > rabbit > 2000 > > > > > fox > 100 > > > bear > 100 > > > > > lion > 80 > > > tiger > 50 > > > > > > and ran it okay in 'Explorer', and text then says to save it to a folder > named 'Soup' which I have done. > On the next page (30) it says to navigate to that folder with the following > code to the python console :- > > cd Soup > > however console rejects that code with the following return: - > > Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)] on > win > 32 > Type "help", "copyright", "credits" or "license" for more information. > >>> cd Soup > File "", line 1 > cd Soup > ^ > SyntaxError: invalid syntax > >>> > > Thank you for reading, hope you can help. > Yours > Simon Evans You're probably supposed to type that in your command-line console (Similar to a Linux terminal), not your Python console. "cd" is a command-line console command. -- https://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
I disagree. I know there's a huge focus on The Big Libraries (and wholesale migration is all but impossible without them), but the long tail of libraries is still incredibly important. It's like saying that migrating the top 10 Perl libraries to Perl 6 would allow people to completely ignore all of CPAN. It just doesn't make sense. -Mark On Thu, Dec 11, 2014 at 6:47 AM, Giampaolo Rodola' wrote: > > > On Wed, Dec 10, 2014 at 5:59 PM, Bruno Cauet wrote: > >> Hi all, >> Last year a survey was conducted on python 2 and 3 usage. >> Here is the 2014 edition, slightly updated (from 9 to 11 questions). >> It should not take you more than 1 minute to fill. I would be pleased if >> you took that time. >> >> Here's the url: http://goo.gl/forms/tDTcm8UzB3 >> I'll publish the results around the end of the year. >> >> Last year results: https://wiki.python.org/moin/2.x-vs-3.x-survey >> >> Thank you >> Bruno >> >> ___ >> Python-Dev mailing list >> python-...@python.org >> https://mail.python.org/mailman/listinfo/python-dev >> Unsubscribe: >> https://mail.python.org/mailman/options/python-dev/g.rodola%40gmail.com >> > > I still think the only *real* obstacle remains the lack of important > packages such as twisted, gevent and pika which haven't been ported yet. > With those ones ported switching to Python 3 *right now* is not only > possible and relatively easy, but also convenient. > > > -- > Giampaolo - http://grodola.blogspot.com > > > ___ > Python-Dev mailing list > python-...@python.org > https://mail.python.org/mailman/listinfo/python-dev > Unsubscribe: > https://mail.python.org/mailman/options/python-dev/wizzat%40gmail.com > > -- https://mail.python.org/mailman/listinfo/python-list
Re: Text Code(from 'Getting Started in Beautiful Soup' re: cd Soup , returns 'Syntax Error, invalid syntax'
Please give your environment when starting a new thread. Python version and OS version. In this case, I'm guessing Windows, because I have to guess something to give a meaningful answer. On 12/11/2014 02:21 PM, Simon Evans wrote: At the start of Chapter 3 of 'Getting Started in Beautiful Soup' it has said to create a html file, 'ecological pyramid.html' - which I have already done re: and ran it okay in 'Explorer', and text then says to save it to a folder named 'Soup' which I have done. On the next page (30) it says to navigate to that folder with the following code to the python console :- cd Soup however console rejects that code with the following return: - Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)] on win 32 Type "help", "copyright", "credits" or "license" for more information. cd Soup File "", line 1 cd Soup ^ SyntaxError: invalid syntax cd is not a Python "command", it's a cmd command. In other words, you type that in your DOS box before starting Python. -- DaveA -- https://mail.python.org/mailman/listinfo/python-list
Re: Text Code(from 'Getting Started in Beautiful Soup' re: cd Soup , returns 'Syntax Error, invalid syntax'
On Fri, Dec 12, 2014 at 6:34 AM, Dave Angel wrote: > Please give your environment when starting a new thread. Python version and > OS version. In this case, I'm guessing Windows, because I have to guess > something to give a meaningful answer. > > On 12/11/2014 02:21 PM, Simon Evans wrote: >> Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)] >> on win >> 32 You mean like how he quoted his Python startup line, thus telling you Python version, word size, and the fact that it's win32? Granted, it would be nice to have that up front, rather than buried deep in the text, but the information _is_ there. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Text Code(from 'Getting Started in Beautiful Soup' re: cd Soup , returns 'Syntax Error, invalid syntax'
On 12/11/2014 02:40 PM, Chris Angelico wrote: On Fri, Dec 12, 2014 at 6:34 AM, Dave Angel wrote: Please give your environment when starting a new thread. Python version and OS version. In this case, I'm guessing Windows, because I have to guess something to give a meaningful answer. On 12/11/2014 02:21 PM, Simon Evans wrote: Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)] on win 32 You mean like how he quoted his Python startup line, thus telling you Python version, word size, and the fact that it's win32? Granted, it would be nice to have that up front, rather than buried deep in the text, but the information _is_ there. Right of course. My eyeballs didn't happen to scan that far to the right. I was looking for drive letters or backslashes, or other clues, but missed the three-letter one "win" or for that matter the "MSC" one, which wouldn't actually have been conclusive. -- DaveA -- https://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
On Thu, Dec 11, 2014 at 11:35 AM, Mark Roberts wrote: > I disagree. I know there's a huge focus on The Big Libraries (and wholesale > migration is all but impossible without them), but the long tail of > libraries is still incredibly important. It's like saying that migrating the > top 10 Perl libraries to Perl 6 would allow people to completely ignore all > of CPAN. It just doesn't make sense. Things in the Python 2.x vs 3.x world aren't that bad. See: https://python3wos.appspot.com/ and https://wiki.python.org/moin/PortingPythonToPy3k http://stromberg.dnsalias.org/~strombrg/Intro-to-Python/ (writing code to run on 2.x and 3.x) I believe just about everything I've written over the last few years either ran on 2.x and 3.x unmodified, or ran on 3.x alone. If you go the former route, you don't need to wait for your libraries to be updated. I usually run pylint twice for my projects (after each change, prior to checkin), once with a 2.x interpreter, and once with a 3.x interpreter (using http://stromberg.dnsalias.org/svn/this-pylint/trunk/this-pylint) , but I gather pylint has the option of running on a 2.x interpreter and warning about anything that wouldn't work on 3.x. -- https://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
On Thu Dec 11 2014 at 3:14:42 PM Dan Stromberg wrote: > On Thu, Dec 11, 2014 at 11:35 AM, Mark Roberts wrote: > > I disagree. I know there's a huge focus on The Big Libraries (and > wholesale > > migration is all but impossible without them), but the long tail of > > libraries is still incredibly important. It's like saying that migrating > the > > top 10 Perl libraries to Perl 6 would allow people to completely ignore > all > > of CPAN. It just doesn't make sense. > > Things in the Python 2.x vs 3.x world aren't that bad. > > See: > https://python3wos.appspot.com/ and > https://wiki.python.org/moin/PortingPythonToPy3k > http://stromberg.dnsalias.org/~strombrg/Intro-to-Python/ (writing code > to run on 2.x and 3.x) > > I believe just about everything I've written over the last few years > either ran on 2.x and 3.x unmodified, or ran on 3.x alone. If you go > the former route, you don't need to wait for your libraries to be > updated. > > I usually run pylint twice for my projects (after each change, prior > to checkin), once with a 2.x interpreter, and once with a 3.x > interpreter (using > http://stromberg.dnsalias.org/svn/this-pylint/trunk/this-pylint) , but > I gather pylint has the option of running on a 2.x interpreter and > warning about anything that wouldn't work on 3.x. > Pylint 1.4 has a --py3k flag to run only checks related to Python 3 compatibility under Python 2. -- https://mail.python.org/mailman/listinfo/python-list
Re: When do default parameters get their values set?
On Wed, Dec 10, 2014, at 21:18, Rustom Mody wrote: > But I have a different question -- can this be demonstrated without the > 'is'? Er, yeah. You can, for example, add an item to one of the dictionaries and observe that it's not present in the other. -- https://mail.python.org/mailman/listinfo/python-list
Re: Python script isn't producing text in data file
On Thursday, December 11, 2014 1:32:02 AM UTC-8, Peter Otten wrote: > Docfxit wrote: > > > I don't know enough about Python to figure out how to isolate where the > > problem is happening. > > Can you get hold of the person who wrote the script? No. I tried. They are not answering their email. Thanks for the suggestion, Docfxit -- https://mail.python.org/mailman/listinfo/python-list
Re: Python 2.x and 3.x use survey, 2014 edition
"Giampaolo Rodola'" writes: > I still think the only *real* obstacle remains the lack of important > packages such as twisted, gevent and pika which haven't been ported > yet. What disqualifies other obstacles from being “*real* obstacles”? How do you determine that? > With those ones ported switching to Python 3 *right now* is not only > possible and relatively easy, but also convenient. If my program relies on an obscure library ‘foo’, and that library is not ported to Python 3, switching to Python 3 is not feasible, and certainly not convenient — regardless of the status of “important packages such as twisted, gevent, and pika”. So your assertion here is plainly false. What is it you're actually wanting to say? -- \“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 -- https://mail.python.org/mailman/listinfo/python-list
Re: is_ as method or property?
Chris Angelico writes: > A property should be used if what you're creating is "virtually an > attribute". Methods are attributes. Are you distinguishing here between “callable attribute” versus “non-callable attribute”? -- \ “Repetition leads to boredom, boredom to horrifying mistakes, | `\ horrifying mistakes to God-I-wish-I-was-still-bored, and it | _o__) goes downhill from there.” —Will Larson, 2008-11-04 | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
Re: is_ as method or property?
On Thu, Dec 11, 2014 at 1:33 PM, Ben Finney wrote: > Chris Angelico writes: > >> A property should be used if what you're creating is "virtually an >> attribute". > > Methods are attributes. Are you distinguishing here between “callable > attribute” versus “non-callable attribute”? Obviously, yes. -- Devin -- https://mail.python.org/mailman/listinfo/python-list
Re: is_ as method or property?
On Fri, Dec 12, 2014 at 8:33 AM, Ben Finney wrote: > Chris Angelico writes: > >> A property should be used if what you're creating is "virtually an >> attribute". > > Methods are attributes. Are you distinguishing here between “callable > attribute” versus “non-callable attribute”? I'm talking conceptually here. You can, for instance, have a stat object which has attribute for the file size and owner, and then it makes equal sense to have an "is_dir" attribute; but that one might be a property, calculated from the file mode. It makes logical design sense for it to be an attribute with the value right there, so it makes design sense for it to be a property. On the other hand, a string will not normally have, as an attribute, a lower-case version of itself, so it makes better sense for that to be a callable method rather than a property. Yes, properties and methods are attributes. That's a technical detail that has nothing to do with the design question of "should this be a property or a method". ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Python Iterables struggling using map() built-in
On Wed, Dec 10, 2014 at 9:01 PM, Steven D'Aprano wrote: > > On Wed, 10 Dec 2014 09:46:55 -0700, Ian Kelly wrote: > > > I don't particularly have a problem with functions having attributes, > > e.g. I think itertools.chain.from_iterable is just peachy. There is a > > downside though, which is that making those functions attributes of > > another function rather than of the module defeats the dir() function > > for that module. > > I think you are missing the point of namespaces :-) > > When I call dir(os), I see os.path, but I don't see the names in os.path. > That is working as designed. I don't think I'm missing the point. os.path is a module. That makes it well suited for a namespace, because that's what modules are designed and expected to provide: the implementation of namespaces. A function, on the other hand, is not well suited to be a namespace, because it's not expected to provide one. When I see a new function, I don't think "I should check what attributes it has." Instead, I wonder about what parameters it takes and what it returns. I expect to be able to open up my web browser and go to the library documentation for the os.path module. I don't expect to find a separate page for statistics.median, because the docs are organized around modules, not functions. Would the median function itself be documented in the statistics page, in the statistics.median page, or redundantly in both? I expect to be able to import modules, and by extension, namespaces. "import os.path" works. "import statistics.median.low" would return an error, as would "from statistics.median import low as median", if that were the only function I wanted. In the latter case I would have to do something like "from statics import median; median = median.low". That's not just ugly; it also demonstrates how the programmer needs to remember and incorporate the detail that this namespace does not work like other namespaces. > As the designer of the module I thought that median_low and median_high > were important enough to include but not important enough to stick in the > main module namespace. To me this sounds backward. Namespaces are a great idea, but at the same time they also create cognitive burden. One creates a namespace because the contents are important enough to be referenced as a group, not because they aren't as important as the other things they're grouped with. The reason the collections ABCs were moved into collections.abc wasn't because they weren't important enough to be in the top-level collections module. -- https://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
2014-12-11 15:47 GMT+01:00 Giampaolo Rodola' : > I still think the only *real* obstacle remains the lack of important > packages such as twisted, gevent and pika which haven't been ported yet. twisted core works on python 3, right now. Contribute to Twisted if you want to port more code... Or start something new, asyncio (with trollius, it works on Python 2 too). The develpoment branch of gevent supports Python 3, especially if you dont use monkey patching. Ask the developers to release a version, at least with "experimental" Python 3 support. I don't know pika. I read "Pika Python AMQP Client Library". You may take a look at https://github.com/dzen/aioamqp if you would like to play with asyncio. > With those ones ported switching to Python 3 *right now* is not only > possible and relatively easy, but also convenient. Victor -- https://mail.python.org/mailman/listinfo/python-list
Re: Do you like the current design of python.org?
Just a gentle reminder that any problems seen with or changes desired to the python.org website need to be documented on its issue tracker at https://github.com/python/pythondotorg/issues/. Key players working on it likely are not aware of discussions here. -- Ned Deily, n...@acm.org -- https://mail.python.org/mailman/listinfo/python-list
Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
On Dec 11, 2014, at 11:35 AM, Mark Roberts wrote: >I disagree. I know there's a huge focus on The Big Libraries (and wholesale >migration is all but impossible without them), but the long tail of >libraries is still incredibly important. It is, but I think it's increasingly the case that packages which don't support Python 3 will either be shamed into it, important enough to get high quality contributed ports, or will be effectively abandoned and alternatives found. This is a big change from where we were several years ago. All my new $work code is Python 3. Some libraries are bilingual but applications start and stay in Python 3-only. Just recently the last two dependencies in Mailman 3 that blocked us from beginning the port to Python 3 have been replaced[1]. We have active branches that are slowly porting own code now[2]. While we can't quite declare victory yet, and there will always be legacy code for which there just aren't the resources to port, I think it's perfectly reasonable for Python 3 to be the default target version for any new code (and a lot of existing code). Cheers, -Barry [1] SQLAlchemy replaced Storm, and Falcon replaced restish in our trunk. [2] https://code.launchpad.net/~barry/mailman/py3 and https://code.launchpad.net/~raj-abhilash1/mailman/py3 pgpsEg8uVRAi1.pgp Description: OpenPGP digital signature -- https://mail.python.org/mailman/listinfo/python-list
Re: When do default parameters get their values set?
Chris Kaynor wrote:
> On Wed, Dec 10, 2014 at 7:15 PM, Steven D'Aprano
> wrote:
>> Using "is" you are demonstrating that calling the function twice returns
>> two distinct objects. That is the purpose of "is", to compare object
>> identity. Without "is", you can compare object IDs directly:
>>
>> id(f()()) == id(f()())
>>
>> but that's ugly and less efficient. Using "is" is the more idiomatic and
>> natural way to do this.
>>
>
> In CPython, that does not work, as the dictionary will be garbage
> collected after each call to id:
f = lambda : (lambda x= {}: x)
f()() is f()()
> False
id(f()()) == id(f()())
> True
Nice catch! Thank you for the correction.
--
Steven
--
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Re: How to detect that a function argument is the default one
Tony the Tiger writes: > radius='10', mass='1' > > if radius == '10' ... > > if mass == '1' ... This ignores the problem as stated: The OP wants to distinguish between a value that was explicitly set by the caller, versus a value that was set by default because the caller did not specify the parameter. The general solution to this is to choose a value outside the domain, a https://en.wikipedia.org/wiki/Sentinel_value> which is different from any value the caller would choose for that parameter. Often, the Python singleton ‘None’ is good for the purpose. I think in this case, where the domain is numeric, a default of ‘None’ would do fine. class Foo: def __init__(centre=(0, 0), radius=None, mass=None): if radius is None: # Caller didn't specify. Set a default value. radius = 10 if mass is None: # Caller didn't specify. Set a default value. mass = 1 self.centre = centre self.radius = radius self.mass = mass In some other cases, ‘None’ is a valid value for the caller to set, and so cannot be used as a sentinel to distinguish the default. For those cases, creating a specific object instance to serve as the sentinel is simple and clear: class Foo: _SENTINEL = object() def __init__(centre=(0, 0), radius=_SENTINEL, mass=_SENTINEL): if radius is _SENTINEL: # Caller didn't specify. Set a default value. radius = 10 if mass is _SENTINEL: # Caller didn't specify. Set a default value. mass = 1 self.centre = centre self.radius = radius self.mass = mass Creating a new object specifically for the sentinel means there is no chance some other value will compare identical. Choosing a leading-underscore name indicates to the reader that this is not part of the public API. -- \“Odious ideas are not entitled to hide from criticism behind | `\ the human shield of their believers' feelings.” —Richard M. | _o__) Stallman | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
Re: Problem with a dialog
ast wrote: > Since try() is a callback function called when a button is pushed, > with the effect to open a dialog, I tried to define MyDialog class > inside try(). The program is the following and it works. I no > longer need to define test as global. > Is it a good practice to define a class inside a function ? Your question is too general. It *can* be good practice, or it can be bad practice. Classes are "first class values" (pun not intended) in Python, which means you can pass them to functions and you can generate them on the fly and return them from functions too. There is a downside to that: classes are fairly hefty objects compared to instances, so if every time you call a function you create an instance of a brand new class instead of re-using the same class, your memory consumption will be much higher. In your case, it probably doesn't matter: you only create a single MyDialog instance, so it shouldn't matter that the class is created dynamically inside the function. But I'm going to suggest a more object oriented solution that avoids the local/global scoping issue completely: * Make test an attribute of MyDialog (what some other languages call "an instance variable"). from tkinter import * import tkinter.simpledialog class MyDialog(tkinter.simpledialog.Dialog): test = True def body(self, master): print(self.test) def apply(self): pass def try_(): setup = MyDialog(root) root = Tk() try_() Technically, what I have done here is make "test" a class attribute, that is, it will be shared by all MyDialog instances. But since there is only one instance, that doesn't matter. Another approach is to forgo the line "test = True" inside the class, and set a per-instance attribute when the instance is created. Add this method to the class: def __init__(self): self.test = True Generally speaking, the __init__ method approach is more common. -- Steven -- https://mail.python.org/mailman/listinfo/python-list
Re: Python Iterables struggling using map() built-in
Ian Kelly wrote:
> A function, on the
> other hand, is not well suited to be a namespace, because it's not
> expected to provide one.
And that is exactly the point I am making about the inherent
conservativeness of Python developers.
Functions ARE namespaces, like instances of user-defined classes they have a
__dict__ and can carry per-instance state. (If you think that only modules
are namespaces, you are badly mistaken. Instances are namespaces too.) This
is *not* an accident of implementation, it is a deliberate design choice.
Contrast functions with builtin functions:
py> def f(): pass
...
py> vars(f)
{}
py> vars(len)
Traceback (most recent call last):
File "", line 1, in
TypeError: vars() argument must have __dict__ attribute
Although functions are written in pure Python, their type is implemented in
C and could easily have been designed to be __dict__-less just like the
builtin_function_or_method type. But they weren't. It is a language feature
that functions are namespaces.
So why don't we use functions as namespaces?
We don't use functions as namespaces because nobody thinks of them as
namespaces, and we don't think of them as namespaces because nobody uses
them as namespaces -- and when somebody tries to break out of that vicious
circle, the conservativeness kicks in and the very idea is rejected.
I think that there is a legitimate debate to be had as to whether this
conservativeness and resistance to change is a good thing or a bad thing,
but I don't think that there should be any debate about the reality of the
Python community being strongly conservative, compared to the "anything
goes" attitude of (say) Ruby, Perl and Lisp programmers. We don't like code
that does anything we haven't seen a hundred times before.
--
Steven
--
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Re: Python Iterables struggling using map() built-in
On Thu, Dec 11, 2014 at 4:28 PM, Steven D'Aprano < steve+comp.lang.pyt...@pearwood.info> wrote: > > Ian Kelly wrote: > > > A function, on the > > other hand, is not well suited to be a namespace, because it's not > > expected to provide one. > > > And that is exactly the point I am making about the inherent > conservativeness of Python developers. > > Functions ARE namespaces, like instances of user-defined classes they have a > __dict__ and can carry per-instance state. (If you think that only modules > are namespaces, you are badly mistaken. Instances are namespaces too.) I never said that functions can't be used as namespaces. I said that functions are *bad* namespaces, and I gave reasons why I think this is true. -- https://mail.python.org/mailman/listinfo/python-list
Re: Python Iterables struggling using map() built-in
On Fri, Dec 12, 2014 at 10:28 AM, Steven D'Aprano wrote: > I think that there is a legitimate debate to be had as to whether this > conservativeness and resistance to change is a good thing or a bad thing, > but I don't think that there should be any debate about the reality of the > Python community being strongly conservative, compared to the "anything > goes" attitude of (say) Ruby, Perl and Lisp programmers. We don't like code > that does anything we haven't seen a hundred times before. I agree that Python is a lot more conservative than many languages, and personally, I think it's good. When it comes to monkeypatching, less is *definitely* better - less places where you have to figure out what import changed the meanings of your built-ins, and so on. (Case in point: A logger replacement tampered with the log.info()/log.error() family of functions, adding a keyword parameter. Took me a fair amount of digging to find out exactly where that happened, and it made REPL importing of the module's functions rather awkward.) The same is true of obscure namespaces, specifically because they're obscure; if I do a JSON decode of something, I'm not going to check to see if numbers came through as a subclass of float with a ".warnings" attribute to tell me about loss of numeric precision, even though that would be perfectly possible. Since almost nobody does this, nobody will expect it to be done, ergo nobody will go looking for it, and the feature may as well not even have been implemented if it's never seen. Popularity *is* sometimes a legitimate argument. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Do you like the current design of python.org?
On 11Dec2014 00:19, Ian Kelly wrote: On Tue, Dec 9, 2014 at 10:16 PM, Cameron Simpson wrote: - the AA menu buttons are all dysfunctional, being purely javascript; it would be better if the menu was styled "display=none" by default, and made visible by javascript With Javascript enabled, the AA menu buttons don't seem to be displayed at all, so I don't understand what the purpose of those is. The point is more that with javascript disabled, the buttons are displayed and nonfunctional. There are also the disappointingly common placeholder characters in various place, for example to the left of each item in the "Socialize" menu. These look like this: http://plus.google.com/+Python";>Google+ I don't know what you mean. Are you saying that you see unrendered HTML to the left of the items? All I see are icons. Along with javascript, the NoScript extension blocks various untrusted objects. Those icons come from a loadable font, which was blocked. If I allow the font to load I get icons. You can imagine the abuse a font load can be used for, such as "I can't unsee that!" icon characters or better still, character transliteration for malicious purpose (we rely on the visual appearance of glyphs to be what we expect). Cheers, Cameron Simpson If people were meant to run around naked, they'd have been born that way. - Rico the Masher, bphei...@ucsvax.ucs.umass.edu -- https://mail.python.org/mailman/listinfo/python-list
Re: Python Script to convert firewall rules
> I am network engineer and not expert in programming. I would like to make > one python script to convert juniper netscreen firewall configuration into > juniper SRX firewall configuration. > Looks pretty tricky, do you have a specification for each format containing all the possible keywords/values? If you could describe the logic in English then writing the equivalent in Python would be straightforward for many people on this list. -- https://mail.python.org/mailman/listinfo/python-list
Re: Python Iterables struggling using map() built-in
In article ,
Ian Kelly wrote:
> I never said that functions can't be used as namespaces. I said that
> functions are *bad* namespaces, and I gave reasons why I think this is true.
An excellent example of functions acting as namespaces is nosetest's
@attr() decorator. We use this, for example, to tag certain test cases
as being reliant on facebook being up(*):
@attr('facebook', 'services')
def test_some_facebook_thing():
# whatever
this lets us turn all those tests on or off with a single switch. The
way @attr() is implemented, it sets attributes on the decorated
function. It's the most logical and obvious place to store a piece of
information about a test case -- right on the test case itself.
Similarly, we've got tests that we annotate as being dependent on itunes
being reachable, depending on certain data existing in the database(**),
being too slow to want to run all the time(**), etc.
(*) and please don't tell me that tests shouldn't depend on external
services.
(**) see first footnote
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beautifulsoup VS lxml
which is more easy and elegant for pulling data out of HTML? -- https://mail.python.org/mailman/listinfo/python-list
Re: beautifulsoup VS lxml
On 12/11/2014 07:02 PM, iMath wrote: > > which is more easy and elegant for pulling data out of HTML? Beautiful Soup is specialized for HTML parsing, and it can deal with badly formed HTML, but if I recall correctly BeautifulSoup can use the lxml engine under the hood, so maybe it's the way to go for you, is it gives you the most flexibility. It certainly has a good API that's easy to use for data scraping. Try it and see if it's acceptable. -- https://mail.python.org/mailman/listinfo/python-list
Extension of while syntax
I was thinking a bit about the following pattern:
value = get_some_value()
while value in undesired_values:
value = get_some_value()
I've always hated code that looks like this. Partly due to the repetition, but
partly also due to the fact that without being able to immediately recognise
this pattern, it isn't very readable.
Python already has one-line syntaxes (e.g. list comprehensions), I was
wondering what people thought about a similar thing with while. It might look
something like:
value = get_some_value() while value in undesired_values()
Perhaps not this exact syntax though, as the parser might try to do `value =
(get_some_value() while...)` instead of `(value = get_some_value) while...`.
Other languages have features which allow something to look slightly less like
this pattern, e.g. Java:
SomeType value;
while ((/* The assignment */ value = getSomeValue()) /* Compare */ ==
undesired_value) {}
Granted, this isn't exactly tidy, but it's a little more DRY and, IMO,
preferable.
What are other's thoughts on this?
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Re: Extension of while syntax
Nelson Crosby writes: > I was thinking a bit about the following pattern: > > value = get_some_value() > while value in undesired_values: > value = get_some_value() I think that's an anti-pattern (because of the repetition, as you say). An improvement:: value = some_default_value_such_as_None while value in undesired_values: value = get_some_value() More common and generally useful:: while True: value = get_some_value() if value not in undesired_values: break > What are other's thoughts on this? I think there are already clean ways to deal with this in common use. https://wiki.python.org/moin/WhileLoop> https://docs.python.org/3/tutorial/controlflow.html#break-and-continue-statements-and-else-clauses-on-loops> -- \ “… one of the main causes of the fall of the Roman Empire was | `\that, lacking zero, they had no way to indicate successful | _o__) termination of their C programs.” —Robert Firth | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
Re: Extension of while syntax
On Fri, Dec 12, 2014 at 1:21 PM, Nelson Crosby wrote:
> I was thinking a bit about the following pattern:
>
> value = get_some_value()
> while value in undesired_values:
> value = get_some_value()
>
> I've always hated code that looks like this. Partly due to the repetition,
> but partly also due to the fact that without being able to immediately
> recognise this pattern, it isn't very readable.
>
> Python already has one-line syntaxes (e.g. list comprehensions), I was
> wondering what people thought about a similar thing with while. It might look
> something like:
You could deduplicate it by shifting the condition:
while True:
value = get_some_value()
if value not in undesired_values: break
But I'm not sure how common this idiom actually is. Usually I'd modify
it, maybe with an iteration limit, or possibly some kind of prompt to
the human. Do you really have this perfectly pure form?
You could rework it to use filter(). I'm not sure that this is in any
way better code, but it is different...
>>> def get_some_value():
return int(input("Enter a value: "))
>>> undesired_values = {1, 2, 3}
>>> next(filter(lambda x: x not in undesired_values, iter(get_some_value,
>>> object(
Enter a value: 3
Enter a value: 1
Enter a value: 2
Enter a value: 1
Enter a value: 3
Enter a value: 1
Enter a value: 2
Enter a value: 7
7
>>>
Look, ma! No duplication!
ChrisA
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Re: [Python-Dev] Python 2.x and 3.x use survey, 2014 edition
On 12/10/2014 5:04 PM, Bruno Cauet wrote: I hesitated a while before deciding not to include it! Apart from python core development what would be the reasons to work mostly on this version ? where 'This version' == 3.5. A possible reason: one is developing an app expected to be released fall 2015 after the 3.5 release and the app depends on something new in 3.5. I must admit though that I cannot think of any such thing now for 3.5. For 3.3 there was the new unicode, which was first committed about a year before release. For 3.4, there was asyncio, but it was not committed until beta1, and was hardly usable then. So it was a defensible position. Anyone who would check 3.5 could just as well check 3.4 and have most of the same impact on the summary. -- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
RE: Extension of while syntax
I would prefer: while value = initial_value in undesired_values: value = get_some_value() Seems I've seen something like this before, C, Perl? Clayton >-Original Message- >From: Python-list [mailto:python-list- >bounces+crk=godblessthe...@python.org] On Behalf Of Ben Finney >Sent: Thursday, December 11, 2014 6:38 PM >To: python-list@python.org >Subject: Re: Extension of while syntax > >Nelson Crosby writes: > >> I was thinking a bit about the following pattern: >> >> value = get_some_value() >> while value in undesired_values: >> value = get_some_value() > >I think that's an anti-pattern (because of the repetition, as you say). > >An improvement:: > >value = some_default_value_such_as_None >while value in undesired_values: >value = get_some_value() > >More common and generally useful:: > >while True: >value = get_some_value() >if value not in undesired_values: >break > >> What are other's thoughts on this? > >I think there are already clean ways to deal with this in common use. > >https://wiki.python.org/moin/WhileLoop> >https://docs.python.org/3/tutorial/controlflow.html#break-and- >continue-statements-and-else-clauses-on-loops> > >-- > \ “… one of the main causes of the fall of the Roman Empire was | > `\that, lacking zero, they had no way to indicate successful | >_o__) termination of their C programs.” —Robert Firth | >Ben Finney > >-- >https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
Re: Extension of while syntax
On 12/11/2014 9:21 PM, Nelson Crosby wrote: I was thinking a bit about the following pattern: value = get_some_value() while value in undesired_values: value = get_some_value() This is do_while or do_until. In Python, write it as do_until in this form. while True: value = get_some_value() if value not in undesired_values: break I've always hated code that looks like this. Partly due to the repetition, but partly also due to the fact that without being able to immediately > recognise this pattern, it isn't very readable. The repetitiion is easily eliminated. value = get_some_value() while value in undesired_values() Forget this, or anything like it, as a 'serious' proposal. -- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
Re: Extension of while syntax
(Please don't top-post; instead, interleave responses inline with the quoted material and trim the excess. See https://en.wikipedia.org/wiki/Posting_style#Interleaved_style>.) "Clayton Kirkwood" writes: > I would prefer: > while value = initial_value in undesired_values: > value = get_some_value() The easy confusion between ‘=’ and ‘==’ in a condition is sufficient that Python doesn't allow the ‘=’ operation in an expression. I think that the subtle errors avoided by that is worth the loss of expressions like the above. -- \ “Pity the meek, for they shall inherit the earth.” —Donald | `\ Robert Perry Marquis | _o__) | Ben Finney -- https://mail.python.org/mailman/listinfo/python-list
Re: PyQt: user interface freezed when using concurrent.futures.ThreadPoolExecutor
在 2014年12月11日星期四UTC+8下午1时25分41秒，Michael Torrie写道： > On 12/10/2014 09:52 PM, iMath wrote: > > I think the user interface shouldn't be freezed when using > > concurrent.futures.ThreadPoolExecutor here,as it executes > > asynchronously , but it doesn't meet my expectations,anyone can > > explain why ? any other solutions here to not let user interface > > freezed? > > > > code is here > > http://stackoverflow.com/questions/27393533/user-interface-freezed-when-using-concurrent-futures-threadpoolexecutor > > In most any GUI framework, regardless of your use of threads, your > callbacks must return control to the main loop immediately (whether an > on-click or an on-timer event), or the GUI *will* freeze. > > You are spawning threads to download the urls, then sitting there > waiting for them to finish in the callback. Of course the GUI will > freeze; your callback is blocking it. What you should be doing is > spawning the threads to do the download, then have the threads (using a > proper QThread mechanism or some other semaphore mechanism) raise a > signal to indicate they are done, which you will then catch in the main > loop as a normal callback. And really when it comes to I/O and GUIs, > asynchronous calls are always better than threads. Not sure what Qt has > in the way of asynchronous i/o calls, and I'm not familiar enough with > the various async i/o frameworks in Python to speak to that, though I > did use Python-Twisted once... very powerful once you get your head > wrapped around it. > > Look through the list archives because in the last 3 or 4 weeks I and > another Python user talked proper thread use with PyQt or PySide, with > code examples. "when it comes to I/O and GUIs, asynchronous calls are always better than threads." I cannot grasp your meaning here, IMO, asynchronous calls are done by using threads. -- https://mail.python.org/mailman/listinfo/python-list
Re: PyQt: user interface freezed when using concurrent.futures.ThreadPoolExecutor
On 12/11/2014 08:20 PM, iMath wrote: > 在 2014年12月11日星期四UTC+8下午1时25分41秒，Michael Torrie写道： >> On 12/10/2014 09:52 PM, iMath wrote: > "when it comes to I/O and GUIs, asynchronous calls are always better than > threads." > > I cannot grasp your meaning here, IMO, asynchronous calls are done by using > threads. Not in your code. All your I/O calls are synchronous; they block until they are finished. But if you mean that calling synchronous calls while in a thread has a similar effect to an asynchronous call, you are correct. But the way you're waiting for the threads to finish, you're blocking your gui. An asynchronous API lets you start long-running I/O calls and define a function that is automatically called upon completion. In other words it's event-driven. Qt may provide everything you need already in an asynchronous form. Check the docs. And use google. Here's a link I found from a google search that illustrates how to fetch a url in Qt using an asynchronous method. You could fire off as many of these as you want, then just wait for signals. http://qt-project.org/wiki/Download_Data_from_URL -- https://mail.python.org/mailman/listinfo/python-list
list comprehension return a list and sum over in loop
Hi there, The list comprehension is results = [d2(t[k]) for k in xrange(1000)], where d2 is a function returning a list, say [x1,x2,x3,x4] for one example. So "results" is a list consisting of 1000 lists, each of length four. Here, what I want to get is the sum of 1000 lists, and then the result is a list of length four. Is there any efficient way to do this? Because I found it is slow in my case. I tried sum(d2(t[k]) for k in xrange(1000)), but it returned error: TypeError: unsupported operand type(s) for +: 'int' and 'list'. Thanks. -- https://mail.python.org/mailman/listinfo/python-list
Re: Extension of while syntax
Chris Angelico : > You could deduplicate it by shifting the condition: > > while True: > value = get_some_value() > if value not in undesired_values: break > > But I'm not sure how common this idiom actually is. Extremely common, and not only in Python. Marko -- https://mail.python.org/mailman/listinfo/python-list
Re: list comprehension return a list and sum over in loop
On 12/12/2014 06:22, KK Sasa wrote: Hi there, The list comprehension is results = [d2(t[k]) for k in xrange(1000)], where d2 is a function returning a list, say [x1,x2,x3,x4] for one example. So "results" is a list consisting of 1000 lists, each of length four. Here, what I want to get is the sum of 1000 lists, and then the result is a list of length four. Is there any efficient way to do this? Because I found it is slow in my case. I tried sum(d2(t[k]) for k in xrange(1000)), but it returned error: TypeError: unsupported operand type(s) for +: 'int' and 'list'. Thanks. I think you need something like this http://stackoverflow.com/questions/19339/a-transpose-unzip-function-in-python-inverse-of-zip I'll let you add the finishing touches if I'm correct :) -- My fellow Pythonistas, ask not what our language can do for you, ask what you can do for our language. Mark Lawrence -- https://mail.python.org/mailman/listinfo/python-list
Re: PyQt: user interface freezed when using concurrent.futures.ThreadPoolExecutor
Michael Torrie : > An asynchronous API lets you start long-running I/O calls and define a > function that is automatically called upon completion. In other words > it's event-driven. Qt may provide everything you need already in an > asynchronous form. GUI developers have been doing event-driven programming for decades. That's an excellent preparation for network programming as well. Unfortunately, the minds of a generation of programmers were contaminated by the thread craze of the 1990's (Java and Windows NT). Marko -- https://mail.python.org/mailman/listinfo/python-list
Re: Python Iterables struggling using map() built-in
On Thu, Dec 11, 2014 at 6:55 PM, Roy Smith wrote:
>
> In article ,
> Ian Kelly wrote:
>
> > I never said that functions can't be used as namespaces. I said that
> > functions are *bad* namespaces, and I gave reasons why I think this is
true.
>
> An excellent example of functions acting as namespaces is nosetest's
> @attr() decorator. We use this, for example, to tag certain test cases
> as being reliant on facebook being up(*):
>
> @attr('facebook', 'services')
> def test_some_facebook_thing():
> # whatever
>
> this lets us turn all those tests on or off with a single switch. The
> way @attr() is implemented, it sets attributes on the decorated
> function. It's the most logical and obvious place to store a piece of
> information about a test case -- right on the test case itself.
I agree this is a great use of function attributes, but this is an example
of tags or annotations, not namespaces. The purpose of namespaces is to
distinguish between different entities of the same name, e.g. 'pow' and
'math.pow' are two distinct functions that both happen to be named pow. We
can tell them apart because they're in separate namespaces.
In the nosetest example, the 'facebook' attribute always means the same
thing no matter which functions you apply it to. Conceptually speaking,
each instance of the attribute is the same annotation. The expression
test_some_facebook_thing.facebook doesn't perform the role of a namespace
because it's used to signify the presence of that annotation, not to
identify something.
A similar example from the standard library is the functools.lru_cache
decorator, which adds a cache_info function to the wrapped function.
However, the cache_info function always performs the same task in relation
to the particular function it decorates, so in this regard it acts more
like an object method than like a name in a namespace.
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Re: Extension of while syntax
On Fri, Dec 12, 2014 at 6:10 PM, Marko Rauhamaa wrote: > Chris Angelico : > >> You could deduplicate it by shifting the condition: >> >> while True: >> value = get_some_value() >> if value not in undesired_values: break >> >> But I'm not sure how common this idiom actually is. > > Extremely common, and not only in Python. Something like it is certainly common, but to justify dedicated syntax, the pure form has to be so amazingly common as to merit it. As soon as you modify the pure form in any way, you need the statement form, for full flexibility. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: PyQt: user interface freezed when using concurrent.futures.ThreadPoolExecutor
On Fri, Dec 12, 2014 at 6:18 PM, Marko Rauhamaa wrote: > GUI developers have been doing event-driven programming for decades. > That's an excellent preparation for network programming as well. > Unfortunately, the minds of a generation of programmers were > contaminated by the thread craze of the 1990's (Java and Windows NT). Threads predate Java and NT, and with a much MUCH better implementation, on OS/2. I don't consider my mind to have been *contaminated* by the OS/2 threading model, which worked superbly. Like all models, it has its limitations, but it's one worth getting your head around IMO. Knowing when to use threads, when to use processes, and when to keep everything in a single thread with some kind of dispatch loop (and *which* dispatch loop) is a valuable skill. But yes, the Windows threading model does have a number of annoying flaws. And I don't remember how Java did things, except that I struggled to find basic fundamental primitives like semaphores, and had to use synchronized functions/objects instead. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Fatal Python error: PyCOND_WAIT(gil_cond) failed
Hi, I am running ipython3 on Unix and constantly see this crash - It happens when i try to issue commands on the ipython interactive shell. I have tried to set the PYTHONDIR to /var/tmp/ in case there was an issue accessing the default location of the history file. However, this makes no difference. I can run a command a few times successfully after which I hit this error. This is my python version info Python 3.3.2 (default, Nov 14 2014, 12:28:17) Type "copyright", "credits" or "license" for more information. IPython 1.1.0 -- An enhanced Interactive Python. ? -> Introduction and overview of IPython's features. %quickref -> Quick reference. help -> Python's own help system. object? -> Details about 'object', use 'object??' for extra details. Any suggestions on what might be going on? Fatal Python error: PyCOND_WAIT(gil_cond) failed Thread 0x088e8900: File "/opt/jde/lib/python3.3/site-packages/IPython/core/history.py", line 664 in _writeout_input_cache File "/opt/jde/lib/python3.3/site-packages/IPython/core/history.py", line 680 in writeout_cache File "/opt/jde/lib/python3.3/site-packages/IPython/core/history.py", line 65 in needs_sqlite File "", line 2 in writeout_cache File "/opt/jde/lib/python3.3/site-packages/IPython/core/history.py", line 733 in run File "/opt/jde/lib/python3.3/site-packages/IPython/core/history.py", line 65 in needs_sqlite File "", line 2 in run File "/opt/jde/lib/python3.3/threading.py", line 637 in _bootstrap_inner File "/opt/jde/lib/python3.3/threading.py", line 614 in _bootstrap Current thread 0x0804b000: File "/opt/jde/lib/python3.3/logging/__init__.py", line 940 in emit File "/opt/jde/lib/python3.3/logging/__init__.py", line 833 in handle File "/opt/jde/lib/python3.3/logging/__init__.py", line 1439 in callHandlers File "/opt/jde/lib/python3.3/logging/__init__.py", line 1377 in handle File "/opt/jde/lib/python3.3/logging/__init__.py", line 1367 in _log File "/opt/jde/lib/python3.3/logging/__init__.py", line 1232 in info File "/var/root/diags/src/lib/python/jde/jde/Model.py", line 644 in show File "", line 1 in File "/opt/jde/lib/python3.3/site-packages/IPython/core/interactiveshell.py", line 2828 in run_code File "/opt/jde/lib/python3.3/site-packages/IPython/core/interactiveshell.py", line 2778 in run_ast_nodes File "/opt/jde/lib/python3.3/site-packages/IPython/core/interactiveshell.py", line 2668 in run_cell File "/opt/jde/lib/python3.3/site-packages/IPython/terminal/interactiveshell.py", line 555 in interact File "/opt/jde/lib/python3.3/site-packages/IPython/terminal/interactiveshell.py", line 436 in mainloop File "/opt/jde/lib/python3.3/site-packages/IPython/terminal/ipapp.py", line 362 in start File "/opt/jde/lib/python3.3/site-packages/IPython/config/application.py", line 545 in launch_instance File "/opt/jde/lib/python3.3/site-packages/IPython/__init__.py", line 118 in start_ipython File "/opt/jde/bin/ipython3", line 6 in Abort (core dumped) -- https://mail.python.org/mailman/listinfo/python-list
Re: Python Script to convert firewall rules
Hi Jason
Thanks for the reply. Yes I can make the all possible keywords/values for both
formate. But after that what gonna be the logic to convert one format to other
format. Like to convert one line below are the keywords:
set interface ethernet2/5 ip 10.17.10.1/24 (format 1)
set interfaces ge-0/0/0 unit 0 family inet address 10.17.10.1/24 (format 2)
(set, interface, ip) = (set, interfaces, family inet address)
But some values are variable and should ask the user to convert manually like
ethernet2/5 equal to ge-0/0/0 or ge-0/0/1 or ge-0/0/2
And some values keep as it is like 10.17.10.1/24
Also then format 2 can be converted int o format 3 (as below) for more
readability of format 2. This is just optional.
interfaces {
ge-2/0/5 {
unit 0 {
family inet {
address 10.17.10.1/24;
}
}
}
}
On Friday, December 12, 2014 5:45:20 AM UTC+4, Jason Friedman wrote:
> I am network engineer and not expert in programming. I would like to make one
> python script to convert juniper netscreen firewall configuration into
> juniper SRX firewall configuration.
>
>
>
> Looks pretty tricky, do you have a specification for each format containing
> all the possible keywords/values?
>
>
> If you could describe the logic in English then writing the equivalent in
> Python would be straightforward for many people on this list.
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