Re: Here's something interesting: sympy crashes in Python 2.6 (Windows)

2008-09-22 Thread Robert Kern

Fredrik Lundh wrote:

Mensanator wrote:


I'm not the one who wrote sympy, so I guess I'm not
the only one who didn't notice it.

If it's a well known problem, then sorry I wasted
your time.


Given that 2.5 explicitly warns about this specific change:

  as = 1
stdin:1: Warning: 'as' will become a reserved keyword in Python 2.6

it's an unknown issue only for people who has 1) never used their code 
under 2.5, or 2) never looks at the output produced by their programs.


The PEP-5 process guarantees that users will have at least a year to 
test their programs and migrate them from use of the deprecated 
construct to the alternative one, and Python 2.5 was released *two* 
years ago.


So it sure looks like the SimPy folks ignored the established process. 
Why they've done that is probably a more interesting issue than the 
change itself.


No warnings show up when importing the offending module:

Python 2.5.1 (r251:54869, Apr 18 2007, 22:08:04)
[GCC 4.0.1 (Apple Computer, Inc. build 5367)] on darwin
Type help, copyright, credits or license for more information.
 from sympy.mpmath import specfun


So what could be suppressing the warning?

--
Robert Kern

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

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Re: Here's something interesting: sympy crashes in Python 2.6 (Windows)

2008-09-22 Thread Fredrik Lundh

Robert Kern wrote:


No warnings show up when importing the offending module:

Python 2.5.1 (r251:54869, Apr 18 2007, 22:08:04)
[GCC 4.0.1 (Apple Computer, Inc. build 5367)] on darwin
Type help, copyright, credits or license for more information.
  from sympy.mpmath import specfun
 

So what could be suppressing the warning?


a bug in Python 2.5, it seems:

 more f1.py
as = 1
as = 2
as = 3
 python f1.py
f1.py:1: Warning: 'as' will become a reserved keyword in Python 2.6
f1.py:2: Warning: 'as' will become a reserved keyword in Python 2.6
f1.py:3: Warning: 'as' will become a reserved keyword in Python 2.6

 more f2.py
as = 1
import os
as = 3
 python f2.py
f2.py:1: Warning: 'as' will become a reserved keyword in Python 2.6

A quick look in parsetok.c reveals that it sets a handling_import flag 
when it stumbles upon an import statement, a flag that's later used to 
suppress the warning message.  The bug is that the flag isn't reset 
until the parser sees an ENDMARKER token (end of file), instead of when 
it sees the next NEWLINE token.


(if someone wants to submit this to bugs.python.org, be my guest)

/F

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Re: Here's something interesting: sympy crashes in Python 2.6 (Windows)

2008-09-22 Thread Terry Reedy

Fredrik Lundh wrote:

Robert Kern wrote:



(if someone wants to submit this to bugs.python.org, be my guest)

http://bugs.python.org/issue3936

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Re: Here's something interesting: sympy crashes in Python 2.6 (Windows)

2008-09-21 Thread Mensanator
On Sep 21, 4:37 am, Fredrik Lundh [EMAIL PROTECTED] wrote:
 Mensanator wrote:
  I'm not the one who wrote sympy, so I guess I'm not
  the only one who didn't notice it.

  If it's a well known problem, then sorry I wasted
  your time.

 Given that 2.5 explicitly warns about this specific change:

   as = 1
 stdin:1: Warning: 'as' will become a reserved keyword in Python 2.6

Uh...how come _I_ don't see that?

In IDLE, I get:

Python 2.5 (r25:51908, Sep 19 2006, 09:52:17) [MSC v.1310 32 bit
(Intel)] on win32

IDLE 1.2
 as = 1
SyntaxError: invalid syntax


When inside a script, I get:

as = 1
print as
 == RESTART ==

1



 it's an unknown issue only for people who has 1) never used their code
 under 2.5, or 2) never looks at the output produced by their programs.

 The PEP-5 process guarantees that users will have at least a year to
 test their programs and migrate them from use of the deprecated
 construct to the alternative one, and Python 2.5 was released *two*
 years ago.

 So it sure looks like the SimPy folks ignored the established process.
 Why they've done that is probably a more interesting issue than the
 change itself.

Is there something wrong with my (and Sympy's) version
of Python that we don't see these warnings?


 /F

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Here's something interesting: sympy crashes in Python 2.6 (Windows)

2008-09-20 Thread Mensanator
Beacuse in 2.6, Python apparently has fixed a discrepency that existed
in previous versions.

In the IDLE that comes with 2.5, typing as, to wit import random as
ran,
the words import and as highlight in red, so you can't use them as
variable
names or you'll get a syntax error.

Ah, but you CAN use as for a variable: for as in xrange(10): print
as
works just fine, although it shouldn't.

Python 2.6 fixes this discrepency and now gives you a syntax error if
you
use as for a variable name.

The upshot is code (such as sympy) written prior to 2.6 can crash now
due
to this fix if said code inadverntently used what should have been a
reserved
word.

I was able to fix the code for this as problem, but not the one that
came after. I've reported this and interested parties can visit the
sympy
page and check Issue 1115.
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Re: Here's something interesting: sympy crashes in Python 2.6 (Windows)

2008-09-20 Thread Guilherme Polo
On Sat, Sep 20, 2008 at 1:27 PM, Mensanator [EMAIL PROTECTED] wrote:
 Beacuse in 2.6, Python apparently has fixed a discrepency that existed
 in previous versions.

 In the IDLE that comes with 2.5, typing as, to wit import random as
 ran,
 the words import and as highlight in red, so you can't use them as
 variable
 names or you'll get a syntax error.

 Ah, but you CAN use as for a variable: for as in xrange(10): print
 as
 works just fine, although it shouldn't.

 Python 2.6 fixes this discrepency and now gives you a syntax error if
 you
 use as for a variable name.

You should have noticed the warning you received in python 2.5 when
using as as a name.


 The upshot is code (such as sympy) written prior to 2.6 can crash now
 due
 to this fix if said code inadverntently used what should have been a
 reserved
 word.

 I was able to fix the code for this as problem, but not the one that
 came after. I've reported this and interested parties can visit the
 sympy
 page and check Issue 1115.
 --
 http://mail.python.org/mailman/listinfo/python-list




-- 
-- Guilherme H. Polo Goncalves
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Re: Here's something interesting: sympy crashes in Python 2.6 (Windows)

2008-09-20 Thread Mensanator
On Sep 20, 1:34�pm, Guilherme Polo [EMAIL PROTECTED] wrote:
 On Sat, Sep 20, 2008 at 1:27 PM, Mensanator [EMAIL PROTECTED] wrote:
  Beacuse in 2.6, Python apparently has fixed a discrepency that existed
  in previous versions.

  In the IDLE that comes with 2.5, typing as, to wit import random as
  ran,
  the words import and as highlight in red, so you can't use them as
  variable
  names or you'll get a syntax error.

  Ah, but you CAN use as for a variable: for as in xrange(10): print
  as
  works just fine, although it shouldn't.

  Python 2.6 fixes this discrepency and now gives you a syntax error if
  you
  use as for a variable name.

 You should have noticed the warning you received in python 2.5 when
 using as as a name.

I'm not the one who wrote sympy, so I guess I'm not
the only one who didn't notice it.

If it's a well known problem, then sorry I wasted
your time.

The sympy people thought it was important and,
as not everyone uses sympy, I thought I was
performing a service to the community mentioning
it here.

Sheesh.




  The upshot is code (such as sympy) written prior to 2.6 can crash now
  due
  to this fix if said code inadverntently used what should have been a
  reserved
  word.

  I was able to fix the code for this as problem, but not the one that
  came after. I've reported this and interested parties can visit the
  sympy
  page and check Issue 1115.
  --
 http://mail.python.org/mailman/listinfo/python-list

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 - Show quoted text -

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