Do I have multiple python on my computer? and how to uninstall one of them?

I encountered the problem that pip install - U numpy did not update the numpy version in python, which is similar to http://ift.tt/1DdASbA

Therefore, I doubt whether I have multiple pythons on my computer.

When I ran which -a python, it returns the following:

/usr/bin/python
/bin/python

Does this mean that I have two python on my computer? If this is true, I want to uninstall one of them. I tried yum remove python. But I could still see these two pythons, when I ran which -a python.