即使安装正确，pip也不能正常工作

Question

我正在尝试设置linux的pip。 我对系统蟒蛇12.7.12，PIP是系统

~/Desktop # sudo easy_install pip 
install_dir /usr/local/lib/python2.7/site-packages/ 
Searching for pip 
Best match: pip 9.0.1 
Processing pip-9.0.1-py2.7.egg 
pip 9.0.1 is already the active version in easy-install.pth 
Installing pip script to /usr/local/bin 
Installing pip2.7 script to /usr/local/bin 
Installing pip2 script to /usr/local/bin 

从这里上安装它看起来PIP正确安装，但是当我试图使用PIP那么它会抛出错误。

pip -V 
Traceback (most recent call last): 
File "/usr/local/bin/pip", line 9, in <module> 
    load_entry_point('pip==9.0.1', 'console_scripts', 'pip')() 
File "/usr/local/lib/python2.7/site-packages/distribute-0.6.14-py2.7.egg/pkg_resources.py", line 305, in load_entry_point 
    return get_distribution(dist).load_entry_point(group, name) 
File "/usr/local/lib/python2.7/site-packages/distribute-0.6.14-py2.7.egg/pkg_resources.py", line 2244, in load_entry_point 
    return ep.load() 
File "/usr/local/lib/python2.7/site-packages/distribute-0.6.14-py2.7.egg/pkg_resources.py", line 1954, in load 
    entry = __import__(self.module_name, globals(),globals(), ['__name__']) 
File "/usr/local/lib/python2.7/site-packages/pip-9.0.1-py2.7.egg/pip/__init__.py", line 28, in <module> 
    from pip.vcs import git, mercurial, subversion, bazaar # noqa 
File "/usr/local/lib/python2.7/site-packages/pip-9.0.1-py2.7.egg/pip/vcs/mercurial.py", line 9, in <module> 
    from pip.download import path_to_url 
File "/usr/local/lib/python2.7/site-packages/pip-9.0.1-py2.7.egg/pip/download.py", line 36, in <module> 
    from pip.utils.glibc import libc_ver 
File "/usr/local/lib/python2.7/site-packages/pip-9.0.1-py2.7.egg/pip/utils/glibc.py", line 4, in <module> 
    import ctypes 
File "/usr/local/lib/python2.7/ctypes/__init__.py", line 7, in <module> 
    from _ctypes import Union, Structure, Array 
****ImportError: /usr/local/lib/python2.7/lib-dynload/_ctypes.so: undefined symbol: PyUnicodeUCS2_FromUnicode**** 

Answer 1

这通常是一个矛盾的/错误的Python安装的症状，而不是Pip。 I.E.它们的构建和编译方式不同。

你有多个Python安装（或类似Travis CI安装/定制安装）？

仅供参考 - here is a similar issue on the Pip bug tracker

我建议你检查什么，当你尝试并运行它的Python安装Python是参考 - 你可以使用类似：

import sys 
print(sys.executable) 

和/或看看使用的virtualenv隔离你正在执行的python环境。

作为另一个参考，我再次相信类似的问题this SO question。