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c++ module, programming, python, python 64, windows

2013-07-07 Build a Python 64 bit extension on Windows 8

I was using MinGW on Windows to build a Python extension including C++ code. The 32bit mode was working fine and I was using the following command line:

python setup.by build --compiler=mingw32
I thought it would be easy to run it with the Python 64 bit version. No change would be required. I was a little bit over confident.
Traceback (most recent call last):
  File "setup.py", line 11, in <module>
    author_email  = '...',
  File "c:\python33_x64\lib\distutils\core.py", line 148, in setup
  File "c:\python33_x64\lib\distutils\dist.py", line 929, in run_commands
  File "c:\python33_x64\lib\distutils\dist.py", line 948, in run_command
  File "c:\python33_x64\lib\distutils\command\build_ext.py", line 323, in run
  File "c:\python33_x64\lib\distutils\ccompiler.py", line 1034, in new_compiler
    return klass(None, dry_run, force)
  File "c:\python33_x64\lib\distutils\cygwinccompiler.py", line 125, in __init__
    if self.ld_version >= "2.10.90":
TypeError: unorderable types: NoneType() >= str()
I decided to switch to Visual Studio Express 2012 to build my extension. but I went through some error related to the file vcvarsall.bat because Python was not able to find the file vsvars64.bat (for one very good reason, it does not exist). I read some blogs where people suggest to reinstall Visual Studio Express but I did not remember the setup asking me anything about options. When I checked the folder of Visual Studio, I found the following file vcvarsx86_amd64.bat. Then, after some research (stubborness is mandatory for those parts) and some tweaks, I discovered two mistakes in the package distutils. They need to be fixed in the file msvc9compiler.py: After the two modifications, it was working fine with the following command line:
python setup.by build --compiler=msvc --plat-name=win-amd64
And I understood why it was failing without any mysterious new installation. I checked about 64 bit version of MinGW but it looked a longer path than the one I chose. Who knows? You will find some others details here. I wrote a function which import a module written in one single C++ file. If the module does not exist, it compiles it inplace.

As a conclusion, I would say it was difficult to find the proper instructions. Maybe the number of documents related to that issue has increased, or the search engines I used were not able to give me the answer. All I know is I do not want to go through that again even if I know there will be a next time when I update Python or when I change my laptop. I hope next time I face that problem, search engines will show me my own page.

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Xavier Dupré