pydeps: Importing a single object from a module results in duplicate imports

Hello, I love the project. It is the only one that works well out of the box and with minimal configuration.

Currently, importing a single object from a module results in a duplicate import in the dependency graph:

the parent module
the child module

E.g.:

# in test_services.py
from telereddit.services.services_wrapper import ServicesWrapper

results in the following dependency graph:

I would expect the graph to not present the services node, because I’m not importing it.

In general, all modules (even if not imported directly) are present and generate duplicate imports arrows. Am I using it wrong, is this intended behavior or is this a bug?

About this issue

Original URL
State: open
Created 4 years ago
Comments: 16 (8 by maintainers)

Most upvoted comments

@gsakkis thanks for the input.

pydeps is internally using a (modified) version of the standard-library module modulefinder which looks for import opcodes in they Python byte code - ie. it neither looks at runtime (e.g. by trying to import the module and look at sys.modules or install an import-hook) nor the source code. This brings with it some disadvantages (we don’t catch especially dynamic imports) and some advantages (we catch both branches of a python-version switch).

Skipping __init__.py files can have unintended consequences, and I believe the current flow comes from fixing a problem with the collections module being excluded (cf. https://github.com/thebjorn/pydeps/commit/1ab3837be41c87f6af055c56188b5a528c5e587a).

I’m pro both configurability and sensible defaults, but I’m not convinced that this behavior (at least not in a simplistic version) is a sensible default.

Removing modules that do not import anything - and have submodules (perhaps provided the removal doesn’t disconnect the graph) would potentially be an interesting flag…

thebjorn on May 1, 2020

@thebjorn an optional flag for the proposed behavior (either on or off by default) would be great!

gsakkis on May 4, 2020

OK - did some research, and apparently pydeps correctly mirrrors python’s documented behavior here. However, most python devs don’t seem to know this and inadvertently create lots of circular imports by putting submodule imports into init files.

Not a problem with pydeps then.

exterm on Nov 30, 2022