Python custom module not found inside an example folder

Question

I'm working in a python project where I'm developing a custom lib (mylib) and using vscode.

/
└── mylib
    └── __init__.py
    ├── ...

If my program split_example.py is on the root, like below, I'm able to import and use mylib.

/
└── mylib
    └── __init__.py
    ├── ...
└── split_example.py

I would like to create a folder called examples and use mylib, but inside the folder examples I'm not able to import and use mylib.

/
└── mylib
    └── __init__.py
    ├── ...
└── examples
    └── split_example.py

Getting the following error:

Traceback (most recent call last):
  File "/home/kleysonr/.vscode/extensions/ms-python.python-2019.11.50794/pythonFiles/ptvsd_launcher.py", line 43, in <module>
    main(ptvsdArgs)
  File "/home/kleysonr/.vscode/extensions/ms-python.python-2019.11.50794/pythonFiles/lib/python/old_ptvsd/ptvsd/__main__.py", line 432, in main
    run()
  File "/home/kleysonr/.vscode/extensions/ms-python.python-2019.11.50794/pythonFiles/lib/python/old_ptvsd/ptvsd/__main__.py", line 316, in run_file
    runpy.run_path(target, run_name='__main__')
  File "/usr/lib/python3.6/runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "/usr/lib/python3.6/runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/data/dev/python/myproject/examples/split_example.py", line 3, in <module>
    from mylib.dataset import split
ModuleNotFoundError: No module named 'mylib'

What should I do to have any program inside the folder examples able to from mylib.dataset import split ?

Related: https://stackoverflow.com/questions/14132789/relative-imports-for-the-billionth-time — fabioconcina, Dec 09 '19 at 13:22

score 1 · Accepted Answer · answered Dec 11 '19 at 20:04

The issue is that because you are executing the code via python examples/split_example.py, Python is making examples/ your current working directory, and thus your mylib directory isn't visible to Python. What you probably would rather do is python -m examples.split_example as that will make the current working directory the project root, making mylib visible to Python.

This will require that you add __init__.py to examples as well.

score -2 · Answer 2 · answered Dec 09 '19 at 13:35

-2

Based on the @fabioconcina comment, I found this solutions.

Just include the following on the top of the file:

from os import sys, path
PARENT_DIR = path.dirname(path.dirname(path.abspath(__file__)))
sys.path.append(PARENT_DIR)

answered Dec 09 '19 at 13:35

Kleyson Rios

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This is a hack. Please use proper package structure conventions. – Piotr Rarus Dec 09 '19 at 13:37
@PiotrRarus-ReinstateMonica may you provide an example ? `mylib` will be available in the pypi and I know that doing a pip install I can use the example without the hack, but I would like to have the examples working if someone just 'git clone' the repo, without pip install the module. That's the intention, have the examples working without installing the module. – Kleyson Rios Dec 09 '19 at 13:53
Move them 1 level up and exclude that folder in setup.py. Check `scikit-learn` [repository](https://github.com/scikit-learn/scikit-learn). – Piotr Rarus Dec 09 '19 at 16:17

Python custom module not found inside an example folder

2 Answers2