Hello, here is a very weird false positive I found.

Minimal reproductible code: https://gist.github.com/bfontaine/551dc93cae6c70df649db43aa859dd4a

Reproduce it:

git clone https://gist.github.com/bfontaine/551dc93cae6c70df649db43aa859dd4a.git
cd 551dc93cae6c70df649db43aa859dd4a
pycycle --here --verbose

Output:

Trying to parse file: /tmp/551dc93cae6c70df649db43aa859dd4a/toto_tutu.py
Trying to parse file: /tmp/551dc93cae6c70df649db43aa859dd4a/tutu.py
Trying to parse file: /tmp/551dc93cae6c70df649db43aa859dd4a/lala.py
Project successfully transformed to AST, checking imports for cycles..
Cycle Found :(
tutu -> lala: Line 2 =>> tutu
Finished.

My environment:

$ pycycle --version
pycycle, version 0.0.8
$ python --version
Python 3.9.6

The first weird thing is that it finds a circular import tutu -> lala -> tutu but lala doesn’t import tutu.

There are other unrelated imports in these files, but if I change or remove a single one of them, the output changes. For example, if I remove import argparse from lala.py, the cycle disappears. If instead I remove import typing from that same file, there’s style a "Cycle Found" but it’s not printed.

It seems that in this moment, the program only takes into account the importation statement in each file, not integrated the python modules loading logic with context, for example, for the tests/_projects/large_circle case, if I change the tests/_projects/large_circle/a_module/a_file.py just by moving the function before import statement like this:

def a_func():
    return "a func"

from a_module.b_module.b_file import b_func

Then this test case should be fine and we can run it successfully, but the program still give us circular import error.

Set default to a string, instead of "False", which causes the type to be "BOOLEAN".

#21

Error: Invalid value for '--source': 'path_to_project/' is not a valid boolean.

Options:
  --source BOOLEAN  Try to find cycles in the path provided.
  --ignore TEXT     Comma separated directories that will be ignored during
                    analysis.

A rather primitive module cycle is not detected. Minimal working example:

reproduction
├── __init__.py
├── moduleA
│   ├── __init__.py
│   └── a_class.py
└── moduleB
    ├── __init__.py
    └── b_class.py

reproduction > moduleA > __init__.py:

from .a_class import ClassA

reproduction > moduleA > a_class.py:

import reproduction.moduleB


class ClassA:
    pass

reproduction > moduleB > __init__.py:

from .b_class import ClassB

reproduction > moduleB > b_class.py:

from ..moduleA import ClassA


class ClassB:
    pass

When running pycycle:

> pycycle --here --verbose
Trying to parse file: /private/tmp/reproduction/reproduction/__init__.py
Trying to parse file: /private/tmp/reproduction/reproduction/moduleB/__init__.py
Trying to parse file: /private/tmp/reproduction/reproduction/moduleB/b_class.py
Trying to parse file: /private/tmp/reproduction/reproduction/moduleA/a_class.py
Trying to parse file: /private/tmp/reproduction/reproduction/moduleA/__init__.py
Project successfully transformed to AST, checking imports for cycles..
No worries, no cycles here!
If you think some cycle was missed, please open an Issue on Github.
Finished.

when trying to import moduleA:

> python3 -c 'import reproduction.moduleA'   
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/private/tmp/reproduction/reproduction/moduleA/__init__.py", line 1, in <module>
    from .a_class import ClassA
  File "/private/tmp/reproduction/reproduction/moduleA/a_class.py", line 1, in <module>
    import reproduction.moduleB
  File "/private/tmp/reproduction/reproduction/moduleB/__init__.py", line 1, in <module>
    from .b_class import ClassB
  File "/private/tmp/reproduction/reproduction/moduleB/b_class.py", line 1, in <module>
    from ..moduleA import ClassA
ImportError: cannot import name 'ClassA' from partially initialized module 'reproduction.moduleA' (most likely due to a circular import) (/private/tmp/reproduction/reproduction/moduleA/__init__.py)

Version: pycycle 0.0.8

Tried to use but --source requires a BOOLEAN and not a string:

Error: Invalid value for '--source': 'path_to_code' is not a valid boolean.

pycycle.exe
Usage: pycycle [OPTIONS] COMMAND [ARGS]...

Options:
  --source BOOLEAN  Try to find cycles in the path provided.
  --ignore TEXT     Comma separated directories that will be ignored during
                    analysis.

My code have structure like this. I have multiple modules and

A modules import B modules to work, B import C and C needs B to work. There are other dependancies are involved as well. But , this is general idea. I get 'No Cycles detected'.

Summary

My example is the following package structure where package.subpackage.module imports from package.module and visa-versa.

.
├── package
│   ├── __init__.py
│   ├── module.py
│   └── subpackage
│       ├── __init__.py
│       └── module.py
└── run.py

run.py

from package.module import Anything

package/subpackage/module.py

from package.module import Anything


class Thing:
    pass

package/module.py

from package.subpackage.module import Thing


class Anything:
    pass

Expected behaviour

I consider this a circular import but pycycle detects no errors.

Executing run.py results in a circular import error:

Traceback (most recent call last):
  File "run.py", line 1, in <module>
    from package.module import Anything
  File "/home/dom/Code/package/package/module.py", line 1, in <module>
    from package.subpackage.module import Thing
  File "/home/dom/Code/package/package/subpackage/module.py", line 1, in <module>
    from package.module import Anything
ImportError: cannot import name 'Anything' from 'package.module' (/home/dom/Code/package/package/module.py)

An archive containing the package structure and code. package.tar.gz