pip installed module but python gives Import error

Question

I have installed grequests using

pip install grequests

when I ran my script, It gave this error:

ImportError: No module named grequests

So, I checked something like this:

pip --version //output: pip 10.0.1 from /usr/local/lib/python2.7/site-packages/pip (python 2.7)

and

python -m pip --version //output: pip 9.0.1 from /Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg (python 2.7)

When I do:

python -m pip install grequests
 Could not fetch URL https://pypi.python.org/simple/grequests/: There was a problem confirming the ssl certificate: [SSL: TLSV1_ALERT_PROTOCOL_VERSION] tlsv1 alert protocol version (_ssl.c:590) - skipping  Could not find a version that satisfies the requirement grequests (from versions: )
 No matching distribution found for grequests