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They are relatively good but absolutely terrible. -- Alan Kay, commenting on Apollos

devel / comp.lang.python / Re: Cyclic imports

Re: Cyclic imports

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From: drsali...@gmail.com (Dan Stromberg)
Newsgroups: comp.lang.python
Subject: Re: Cyclic imports
Date: Sat, 21 Aug 2021 15:35:21 -0700
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by: Dan Stromberg - Sat, 21 Aug 2021 22:35 UTC

On Tue, Aug 17, 2021 at 11:20 AM Chris Angelico <rosuav@gmail.com> wrote:

> The main advantage of ast.parse() is that it no longer cares about
> code layout, and it won't be fooled by an import statement inside a
> docstring, or anything like that. It's also pretty easy to handle
> multiple variants (note how "import bar, baz" just has two things in
> the names list).
>

I put together something to detect importcycles using the ast module. It's
at https://stromberg.dnsalias.org/svn/cycles/trunk for now - no pypi, no
homepage. I've only run it on some test inputs, nothing substantial.
Usage example is in the Makefile.

Imports are kind of complicated. Am I missing any important cases?

Sample output looks like:
Detected 2 cycles:
('mutual_1', 'mutual_2')
('directory.mutual_a', 'directory.mutual_b', 'directory.mutual_c')

Thanks!