If you install libraries with
pip
command you might find yourself in the following situation:
root@srv:~# pip Traceback (most recent call last): File "/usr/bin/pip", line 9, in <module> from pip import main File "/usr/lib/python2.7/dist-packages/pip/__init__.py", line 13, in <module> from pip.exceptions import InstallationError, CommandError, PipError File "/usr/lib/python2.7/dist-packages/pip/exceptions.py", line 6, in <module> from pip._vendor.six import iteritems File "/usr/lib/python2.7/dist-packages/pip/_vendor/__init__.py", line 64, in <module> vendored("cachecontrol") File "/usr/lib/python2.7/dist-packages/pip/_vendor/__init__.py", line 36, in vendored __import__(modulename, globals(), locals(), level=0) File "/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl/cachecontrol/__init__.py", line 9, in <module> File "/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl/cachecontrol/wrapper.py", line 1, in <module> File "/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl/cachecontrol/adapter.py", line 3, in <module> File "/usr/share/python-wheels/requests-2.9.1-py2.py3-none-any.whl/requests/__init__.py", line 53, in <module> File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/contrib/pyopenssl.py", line 54, in <module> File "/usr/local/lib/python2.7/dist-packages/OpenSSL/__init__.py", line 8, in <module> from OpenSSL import rand, crypto, SSL File "/usr/local/lib/python2.7/dist-packages/OpenSSL/SSL.py", line 124, in <module> SSL_ST_INIT = _lib.SSL_ST_INIT AttributeError: 'module' object has no attribute 'SSL_ST_INIT'