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Custom importer and errors

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From: python@aliases.systohc.net (Fabiano Sidler)
Newsgroups: comp.lang.python
Subject: Custom importer and errors
Date: Sat, 13 Apr 2024 20:49:15 +0200
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by: Fabiano Sidler - Sat, 13 Apr 2024 18:49 UTC

Hi folks!

I'd like to split my package tree into several IDE projects and build a
custom
importer to import
'top.child1.child2'
from the directory
<python-path-entry>/top.child1.child2/__init__.py
so basically replacing the dots with slashes and having the package content
lying directly in the project folder. I have come up with this:

=== usercustomize.py ===
1 import sys
2 from importlib.machinery import ModuleSpec
3 from pathlib import Path
4
5 Loader = type(__spec__.loader)
6
7 class IdeHelper:
8     @classmethod
9     def find_spec(cls, name, path, target=None):
10         for dirname in sys.path:
11             dirobj = Path(dirname)
12             if dirobj.name == name:
13                 break
14         else:
15             return None
16         origin = str(dirobj.joinpath('__init__.py').absolute())
17         ret = ModuleSpec(name, Loader(name, origin), origin=origin)
18         return ret
19
20 sys.meta_path.append(IdeHelper)

which I'm on the right direction with. Unfortunately, I'm getting errors
while
importing a subpackage. With 'import top.child1' the error is
ModuleNotFoundError: No module named 'top.child1'; 'top' is not a
package
whereas with 'from top import child1' the error changes to
ImportError: cannot import name 'child1' from 'top' (unknown location)

How can I make this work?

Best wishes,
Fabiano

The only thing worse than X Windows: (X Windows) - X

devel / comp.lang.python / Custom importer and errors

Subject	Author
Custom importer and errors	Fabiano Sidler