PIP: Installing only the dependencies

Question

I have a script that creates a virtualenv, installs distribute and pip in it and then optionally clones a git repo.

Now I have the project I will be working on, installed. But its dependencies are not installed. How can I make pip install all the dependencies as if I have issued a pip install MyApp?

EDIT: Appareantly my question is a duplicate of this one.

Not exactly sure but pip install -e . seems to do what I want without too many extra stuff lying around. I'd prefer if my code wasn't linked from site-packages though.

Answer 1

In my package root issuing pip install -e . installs dependencies.

Answer 2

You should use the pip requirements file.

Essentially, place all your requirements, one in each line in a file and pass that to pip using the command

pip install -r requirements.txt

What more, if you have a standard environment, pip can actually dump such a file from existing installs using the command:

pip freeze

You can put the file thus generated directly into the pip requirements, and call the previous command from your deployment script.

Pretty cool, isnt it? :)

Answer 3

If your dependencies are defined in the setup.py file, you can first dump them to an external file using:

python setup.py egg_info

This will list all your dependencies in YOUR_PROJECT.egg-info/requires.txt file. Then you can install them using pip:

pip install -r *.egg-info/requires.txt