The best tool I’ve found is called pyan, and was originally written by Edmund Horner, improved by him, and then given colorization and other features by Juha Jeronen. That version has useful commandline options:
Usage: pyan.py FILENAME... [--dot|--tgf]
Analyse one or more Python source files and generate an approximate call graph
of the modules, classes and functions within them.
Options:
-h, --help show this help message and exit
--dot output in GraphViz dot format
--tgf output in Trivial Graph Format
-v, --verbose verbose output
-d, --defines add edges for 'defines' relationships [default]
-n, --no-defines do not add edges for 'defines' relationships
-u, --uses add edges for 'uses' relationships [default]
-N, --no-uses do not add edges for 'uses' relationships
-c, --colored color nodes according to namespace [dot only]
-g, --grouped group nodes (create subgraphs) according to namespace
[dot only]
-e, --nested-groups create nested groups (subgraphs) for nested namespaces
(implies -g) [dot only]
Here’s the result of running pyan.py --dot -c -e pyan.py | fdp -Tpng:
Edmund Horner’s original code is now best found in his github repository, and somebody has also made a repository with both versions, from where you can download Juha Jeronen’s version. I’ve made a clean version combining their contributions into my own repository just for pyan, since both repositories have lots of other software.