In general, don't do this:
pip install package
because, as you have correctly noticed, it's not clear what Python version you're installing package
for.
Instead, if you want to install package
for Python 3.7, do this:
python3.7 -m pip install package
Replace package
with the name of whatever you're trying to install.
Took me a surprisingly long time to figure it out, too. The docs about it are here.
Your other option is to set up a virtual environment. Once your virtual environment is active, executable names like python
and pip
will point to the correct ones.