Python package dependency tree
dependency-management, pypi, python
Solution
You should be looking at the `install_requires` field instead, see New and changed `setup` keywords.
`requires` is deemed too vague a field to rely on for dependency installation. In addition, there are `setup_requires` and `test_requires` fields for dependencies required for `setup.py` and for running tests.
Certainly, the dependency graph has been analyzed before; from this blog article by Olivier Girardot comes this fantastic image:
The image is linked to the interactive version of the graph.
Problem
I would like to analyze the dependency tree of Python packages. How can I obtain this data? Things I already know - `setup.py` sometimes contains a `requires` field that lists package dependencies - PyPi is an online repository of Python packages - PyPi has an API Things that I don't know - Very few projects (around 10%) on PyPi explicitly list dependencies in the `requires` field but `pip/easy_install` still manage to download the correct packages. What am I missing? For example the popular library for statistical computing, `pandas`, doesn't list `requires` but still manages to install `numpy`, `pytz`, etc.... Is there a better way to automatically collect the full list of dependencies? - Is there a pre-existing database somewhere? Am I repeating existing work? - Do similar, easily accessible, databases exist for other languages with distribution systems (R, Clojure, etc...?)