[Python] Python Equivalent of npm or rubygem

If you don't already have virtualenv installed, then install it globally with: pip install virtualenv (or pip3 - for python3)

Each Python project should have its own virtualenv installation. It's easy to set one up, just cd to your project's root and:python3 -m virtualenv env # creates env folder with everything you need

Activate virtualenv: source env/bin/activate

Deactivate virtualenv: deactivate

Now, any interaction with pip is contained within your project.

Run pip install package_name==version for each of your dependencies. They are installed in ./env/lib/python3.x/site-packages/

When you want to save your project's dependencies to a file, run:

pip freeze > requirements.txt

You actually don't need -l or --local if you're in an activated project-specific virtualenv (which you should be).

Now, when you want to install your dependencies from requirements.txt, set up your virtualenv, and run:

pip install -r requirements.txt

That's all.