Invalid "Module import itself" error for namespace packages.

[feluxe]

Steps to reproduce

You can either clone this repo to get the test file tree:

git clone https://github.com/feluxe/test_pylint_ns_package_err.git

cd into it and run pipenv install --dev --pre

or create the file tree manually with the following steps:

Create test file tree manually:

Create this file tree:

tmp_pylint_err
├── nspackage
│   ├── mypackage
│   │   └── __init__.py
│   └── sty
│       └── __init__.py
└── test.py

Next, install pylint and sty from pypi in a Python 3.7 virtualenv:

pipenv install --dev --pre pylint sty

We add this line to nspackage/mypackage/__init__.py:

from nspackage.sty import fg

We add this line to nspackage/sty/__init__.py:

from sty import *

We add these lines to test.py:

from nspackage.sty import fg
from nspackage.mypackage import fg as fg2

print(f"{fg.green}hello1{fg.rs}")
print(f"{fg2.green}hello2{fg2.rs}")

Current behavior

Note: As you can see in the project file tree, nspackage is a name space package omitting __init__.py.

If I run pipenv run pylint nspackage, I get these errors:

************* Module sty
nspackage/sty/__init__.py:1:0: W0406: Module import itself (import-self)
************* Module mypackage
nspackage/mypackage/__init__.py:1:0: E0611: No name 'fg' in module 'nspackage.sty' (no-name-in-module)

Expected behavior

I think the example project is valid Python and pylint should not complain.

You can run test.py for validation:

pipenv run python test.py

which runs just fine.

pylint --version output

pylint 2.2.2
astroid 2.1.0
Python 3.7.1 (default, Nov 11 2018, 02:35:35) 
[GCC 8.2.1 20180831]

[PCManticore]

Thanks for reporting an issue!

[Oberon00]

At opentelemetry/opentelemetry-python, we have the same issue and it's very annoying as we would like to add companion modules for widely-used libraries that are named the same as the corresponding library, but in a different package.

EDIT: astroid==2.3.1,pylint==2.4.2
Python 3.7.3

[Oberon00]

It's very likely that #2862 is the same problem but that issue has a nicer repro.

[Oberon00]

Also, the topic-import-system label seems to be missing on this issue.

[erensahin]

I run into the same problem when I use namespace packages. My pylint version is 2.4.4, I tried with more recent versions but it does not solve at all. Any suggestions?

[Pierre-Sassoulas]

Did you try to install from scratch (do you have the latest astroid version too) ? This issue seems related to #5235 it might be a solution. If you have an example of repository with namespace feel free to comment on it :)

[erensahin]

Thanks! I uninstalled pylint and astroid, and re-installed pylint with its latest version (2.13.4).

I will try to explain the package structure. The problem is, namespace package name conflicts with another python library name (it is an internal one, so I will pick pandas as an example);

├── namespace_pkg
│   ├── pandas
│   │   └── __init__.py
│   └── something_else
│       └── __init__.py

The content of namespace_pkg/pandas/init.py is as follows;

cat namespace_pkg/pandas/__init__.py

from pandas import DataFrame
df = DataFrame([[1,2]])
print(df)

When I run the file directly as python namespace_pkg/pandas/__init__.py, I don't encounter any problem at all;

   0  1
0  1  2

But when I run pylint: pylint namespace_pkg/, I get the error as;

namespace_pkg/pandas/__init__.py:1:0: W0406: Module import itself (import-self)

[erensahin]

Did you try to install from scratch (do you have the latest astroid version too) ? This issue seems related to #5235 it might be a solution. If you have an example of repository with namespace feel free to comment on it :)

Plus, #5235 looks quite promising for my problem :)

[Pierre-Sassoulas]

Plus, #5235 looks quite promising for my problem :)

Can you try installing pylint with : pip install -U git+https://github.com/hmc-cs-mdrissi/@add_option_disable_sys_path_patching and launch pylint with disable-path-patching=y in your pylintrc for the [master] section, to see if it fix the issue, please ?

[erensahin]

disable-path-patching

Yeah, it does fix it. Thanks :)

btw, the correct pip install command should be as;

pip install -U git+https://github.com/hmc-cs-mdrissi/pylint/@md/add_option_disable_sys_path_patching

[DanielNoord]

@Pierre-Sassoulas Can we use this example to create a folder structure to test on in the primer?

[Pierre-Sassoulas]

Yes, I was thinking we should use something else than pandas, like pathlib, so we don't have to add dependencies to pandas.

[erensahin]

@Pierre-Sassoulas do you have any planned timeline for the next release? when we can get the new feature implemented in #5235 :)

[Pierre-Sassoulas]

You can check https://github.com/PyCQA/pylint/milestone/61 to see the next patch release addvancement. It depends on the availability of implementers and reviewer but soonish ™️

[DanielNoord]

I have been working on a fix in #6405.

For anybody affected by this, please let me know if the changes in that PR fix your issues with linting of namespace packages.