There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

 No module named yum

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.7.10 (default, Sep 5 2017, 17:35:43) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-3)]

If you cannot solve this problem yourself, please go to 
the yum faq at:
 http://yum.baseurl.org/wiki/Faq

Traceback (most recent call last):
 File "/usr/bin/pip2", line 5, in <module>
 from pkg_resources import load_entry_point
ImportError: No module named pkg_resources

which python

vim /usr/bin/yum