Workaround for virtual environments (VirtualEnv)

[CristiFati]

pip installing v226 in a (VirtualEnv based) virtual environment (not sure f this is an officially supported configuration) makes it unusable:

[prompt]> ".\venv_py_064_030800\Scripts\python.exe" -m pip list
Fatal Python error: init_import_size: Failed to import the site module
Python runtime state: initialized
Traceback (most recent call last):
  File "e:\Work\Dev\StackOverflow\q058805040\venv_py_064_030800\lib\site.py", line 769, in <module>
    main()
  File "e:\Work\Dev\StackOverflow\q058805040\venv_py_064_030800\lib\site.py", line 746, in main
    paths_in_sys = addsitepackages(paths_in_sys)
  File "e:\Work\Dev\StackOverflow\q058805040\venv_py_064_030800\lib\site.py", line 279, in addsitepackages
    addsitedir(sitedir, known_paths)
  File "e:\Work\Dev\StackOverflow\q058805040\venv_py_064_030800\lib\site.py", line 202, in addsitedir
    addpackage(sitedir, name, known_paths)
  File "e:\Work\Dev\StackOverflow\q058805040\venv_py_064_030800\lib\site.py", line 170, in addpackage
    exec(line)
  File "<string>", line 1, in <module>
  File "e:\Work\Dev\StackOverflow\q058805040\venv_py_064_030800\lib\site-packages\win32\lib\pywin32_bootstrap.py", line 14, in <module>
    for maybe in site.getsitepackages():
AttributeError: partially initialized module 'site' has no attribute 'getsitepackages' (most likely due to a circular import)

Just to make things clear: there's nothing wrong with PyWin32, it's just a fix applied on PyWin32's side to work around a VirtualEnv bug.

More details on [SO]: PyWin32 (226) and virtual environments (@CristiFati's answer).