Build a Call graph in python including modules and functions? [closed]
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 graphof 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.
You might want to check out pycallgraph:
Also in this link a more manual approach is described:
generating-call-graphs-for-understanding-and-refactoring-python-code
In short, no such tool exists. Python is far too dynamic of a language to be able to generate a call graph without executing the code.
Here's some code which clearly demonstrates some of the very dynamic features of python:
class my_obj(object): def __init__(self, item): self.item = item def item_to_power(self, power): return self.item ** powerdef strange_power_call(obj): to_call = "item_to_power" return getattr(obj, to_call)(4)a = eval("my" + "_obj" + "(12)")b = strange_power_call(a)
Note that we're using eval
to create an instance of my_obj
and also using getattr
to call one of its methods. These are both methods that would make it extremely difficult to create a static call graph for python. Additionally, there are all sorts of difficult to analyze ways of importing modules.
I think your best bet is going to be to sit down with the code base and a pad of paper, and start taking notes by hand. This will have the dual benefit of making you more familiar with the code base, and will not be easily tricked by difficult to parse scenarios.