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)

2008-09-22 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)



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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
: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)

2008-09-21 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
> :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?

>
> 

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

2008-09-21 Thread Fredrik Lundh

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
: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.




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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
>
> --
> -- Guilherme H. Polo Goncalves- Hide quoted text -
>
> - Show quoted text -

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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
>



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-- Guilherme H. Polo Goncalves
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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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