originally, pip version 9 has been used very well under python2. After updating pip version 10, there are the following errors in whatever pip is installed, and there are all kinds of troubles for several hours, or there is no way to solve the great god!

text version:

Traceback (most recent call last):

File "c:python27librunpy.py", line 174, in _ run_module_as_main

"__main__", fname, loader, pkg_name)

File "c:python27librunpy.py", line 72, in _ run_code

exec code in run_globals

File "C:Python27Scriptspip2.exe__main__.py", line 5, in < module >

ImportError: cannot import name main