An alternative is to call the pip module by using python2.7, as below:
python2.7 -m pip <commands>
For example, you could run python2.7 -m pip install <package> to install your favorite python modules. Here is a reference: https://stackoverflow.com/a/50017310/4256346.
In case the pip module has not yet been installed for this version of python, you can run the following:
python2.7 -m ensurepip
Running this command will "bootstrap the pip installer". Note that running this may require administrative privileges (i.e. sudo). Here is a reference: https://docs.python.org/2.7/library/ensurepip.html and another reference https://stackoverflow.com/a/46631019/4256346.