Does python pip have the equivalent of node's package.json?

Once all necessary packages are added

pip freeze > requirements.txt

creates a requirement file.

pip install -r requirements.txt

installs those packages again, say during production.

yes, its called the requirements file:

https://pip.readthedocs.io/en/1.1/requirements.html

you can specify the package name & version number.

you can also specify a git url or a local path

in the usual case, you would specify the package followed by the version num, e.g.

sqlalchemy=1.0.1

you can install all the packages specified in a requirements.txt file through the command

pip install -r requirements.txt