Where python keeps --prefix(sys.prefix) settings?

Question

So my question is about where is it?

And is where any way to change that?

Something goes wrong on my Windows 8 machine.

PYTHONPATH=C:\Python27;C:\Python27\Lib

Output from python:

>>> import sys
>>> sys.prefix
'C:\\Python27'

Same here:

python -c "import sys; print sys.prefix"
C:\Python27

From ipython:

ipython -c "import sys; print sys.prefix"

Defaulting color scheme to 'NoColor'
c:\Python27 # low c

And finally I have trouble with virtualenv:

Traceback (most recent call last):
  File "C:\Python27\Lib\runpy.py", line 162, in _run_module_as_main
    "__main__", fname, loader, pkg_name)
  File "C:\Python27\Lib\runpy.py", line 72, in _run_code
    exec code in run_globals
  File "C:\Python27\Scripts\virtualenv.exe\__main__.py", line 9, in <module>
  File "c:\python27\lib\site-packages\virtualenv.py", line 832, in main
    symlink=options.symlink)
  File "c:\python27\lib\site-packages\virtualenv.py", line 994, in create_environment
    site_packages=site_packages, clear=clear, symlink=symlink))
  File "c:\python27\lib\site-packages\virtualenv.py", line 1192, in install_python
    copy_required_modules(home_dir, symlink)
  File "c:\python27\lib\site-packages\virtualenv.py", line 1130, in copy_required_modules
    dst_filename = change_prefix(filename, dst_prefix)
  File "c:\python27\lib\site-packages\virtualenv.py", line 1095, in change_prefix
    (filename, prefixes)
AssertionError: Filename C:\Python27\Lib\os.py does not start with any of these prefixes: ['c:\\python27']

Why they are different?

So fast solution is just to change PYTHONPATH with low 'c', it seems ugly.

They are all the same, except the error shows something is being matched case-insensitively. — Martijn Pieters, Nov 03 '15 at 15:48
Note that ``\\`` is just the string representation giving you properly escaped backslashes. Use `print sys.prefix` if you want to see the value without escaping. — Martijn Pieters, Nov 03 '15 at 15:49
You'll need to show us the full traceback, I don't know what code is throwing that exception. — Martijn Pieters, Nov 03 '15 at 15:52
And that `ipython` shows the path with a lowercase `c` is.. unexpected and a little weird. Not sure how that happened. — Martijn Pieters, Nov 03 '15 at 15:53
Huh, I've just noticed that in `traceback` a bunch of different cases.. I am using git bash and probably made some `pip install` thorugh it. — xiº, Nov 03 '15 at 15:57
I do think virtualenv should be doing the check case-insensitively there (using [`os.path.normcase()`](https://docs.python.org/2/library/os.path.html#os.path.normcase)). I'll see about filing a bug.. — Martijn Pieters, Nov 03 '15 at 16:38

Where python keeps --prefix(sys.prefix) settings?

0 Answers0