Sympy on python 3 - mpmath

[dennis]

Hi,

I downloaded sympy from git and ran "bin/use2to3" but seems that it does not convert mpmath. The directory is missing in "py3k-sympy".

I get the following error:

>>> import sympy

Traceback (most recent call last):

  File "<stdin>", line 1, in <module>

  File "sympy\__init__.py", line 49, in <module>

    from sympy.core import *

  File "sympy\core\__init__.py", line 8, in <module>

    from .expr import Expr, AtomicExpr

  File "sympy\core\expr.py", line 4, in <module>

    from .evalf import EvalfMixin

  File "sympy\core\evalf.py", line 6, in <module>

    import sympy.mpmath.libmp as libmp

ImportError: No module named mpmath.libmp

Any ideas?

[Aaron Meurer]

I'd say that this is a bug. The paths in your traceback suggest that
you're on Windows, which unfortunately, few of us are able to test.

Can you file an issue in our tracker for this?

Aaron Meurer

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[Ronan Lamy]

Try to run bin/use2to3 again, it's been known to forget files sometimes,
for no apparent reason.

[Aaron Meurer]

Also try it in https://github.com/sympy/sympy/pull/726, which
apparently *still* hasn't been merged.

Aaron Meurer

[dennis]

I tried on linux and it converts fine and the converted files can be run with python3 on windows. This solves my problem.

How do I download the sympy code with the pull request to try converting on windows? 

[Aaron Meurer]

There is a guide at the botton of the pull request on how to get it
(click on "help" after "comment on this pull request"). Or here's a
little guide of my own

- Navigate to the user's repo who has the pull request. In this case,
you would use https://github.com/vperic/sympy/.

- Click on the copy icon after the clone url. This should put
something like https://github.com/vperic/sympy.git on your clipboard.

Type

git remote add vperic https://github.com/vperic/sympy.git # Change
vperic to the username if it's a different user
git fetch vperic
git checkout vperic/branchname

You can get the branch name from the top of the pull request (it's in
a black box). In this case, it's use2to3-fixes.

If the branch is outdated against master and you need recent changes
from both, you can do

git merge master

at this point to put them together.

If you do try this branch (or any branch), please comment on the pull
request if it works or if it doesn't work for you.

Aaron Meurer

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[dennis]

I don't know if I did everything correctly, but it seems that it doesn't work. When running bin/use2to3, i get this error:

Removed trailing whitespace from py3k-sympy\sympy\physics\quantum\represent.py

Traceback (most recent call last):

  File "bin/use2to3", line 132, in <module>

    text = f.read()

  File "C:\Python32\lib\encodings\cp1252.py", line 23, in decode

    return codecs.charmap_decode(input,self.errors,decoding_table)[0]

UnicodeDecodeError: 'charmap' codec can't decode byte 0x81 in position 5511: cha

racter maps to <undefined>

[Aaron Meurer]

Can you open an issue for this in our issue tracker
(http://code.google.com/p/sympy/issues/list)? I've never seen this
error before, but that's probably because I don't use Windows.

Aaron Meurer

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[Chris Smith]

What version of sympy are you using? There are no problems for me under 32bit windows.

[dennis]

I am using:

Windows 7 32-bit 

Python 3.2.2

sympy cloned from git repository (https://github.com/sympy/sympy.git)

Should I use a released version of sympy for this (0.7.1)?

[Aaron Meurer]

No, the released version does not support Python 3 (and anyway, we
won't ship use2to3, but rather, just pre-built Python 3 sources).

Aaron Meurer

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