[FIXED] Python pytest - ModuleNotFoundError: No module named 'prompts'

Issue

Running pytest in the terminal results in the below error. The application runs fine with python3 main.py from the src/ directory, however pytest throws this error.

____________________________________________________________________________________ ERROR collecting tests/test_with_pytest.py ____________________________________________________________________________________
    ImportError while importing test module '/Users/Lucas/Library/Mobile Documents/com~apple~CloudDocs/Documents/tests/test_with_pytest.py'.
    Hint: make sure your test modules/packages have valid Python names.
    Traceback:
    /usr/local/Cellar/[email protected]/3.11.5/Frameworks/Python.framework/Versions/3.11/lib/python3.11/importlib/__init__.py:126: in import_module
        return _bootstrap._gcd_import(name[level:], package, level)
    tests/test_with_pytest.py:1: in <module>
        from src import csv_methods
    src/csv_methods.py:2: in <module>
        from prompts import *
    E   ModuleNotFoundError: No module named 'prompts'

I am using pipenv for the virtual env.

Project structure:

├── Pipfile
├── Pipfile.lock
├── README.md
├── __pycache__
│   └── ...
├── requirements.txt
├── src
│   ├── __init__.py
│   ├── __pycache__
│   │   └── ...
│   ├── app_objects.md
│   ├── asset.py
│   ├── command_line.py
│   ├── csv_data
│   │   └── assets.csv
│   ├── csv_methods.py
│   ├── input.py
│   ├── log.log
│   ├── main.py
│   ├── menu.py
│   └── prompts.py
└── tests
    ├── __init__.py
    └── test_with_pytest.py

I have tried the popular answers and common results such as adding __init__.py files within the test, src folder and the route directory. Note the init.py files are blank, I have tried the recommendations from the following posts such as adding in here here and here

I saw the solution about adding PYTHONPATH=. pytest to the project but its unclear in which file etc to add this.

Also tried running with python3 -m pytest but no luck.

python3 -m site

sys.path = [
    '/Users/Lucas/Library/Mobile Documents/com~apple~CloudDocs/Documents/',
    '/usr/local/Cellar/[email protected]/3.11.5/Frameworks/Python.framework/Versions/3.11/lib/python311.zip',
    '/usr/local/Cellar/[email protected]/3.11.5/Frameworks/Python.framework/Versions/3.11/lib/python3.11',
    '/usr/local/Cellar/[email protected]/3.11.5/Frameworks/Python.framework/Versions/3.11/lib/python3.11/lib-dynload',
    '/Users/Lucas/.local/share/virtualenvs/asset_management_system-GiLvwx5p/lib/python3.11/site-packages',
]
USER_BASE: '/Users/Lucas/Library/Python/3.11' (doesn't exist)
USER_SITE: '/Users/Lucas/Library/Python/3.11/lib/python/site-packages' (doesn't exist)
ENABLE_USER_SITE: False

css_methods.py

#  Functions to perform read, write to csv data stores
from prompts import *
import csv
import os
from tabulate import tabulate
import logging

---snip---

test_with_pytest.py

from src import csv_methods
from src import prompts

def test_always_passes():
    assert True

Pipfile.lock

"_meta": {
        "hash": {
            "sha256": "d2f84cfd3b709ff81d112ff5862ef667b82358c63d00cdf29b529b0535b4c08a"
        },
        "pipfile-spec": 6,
        "requires": {
            "python_version": "3.11"
        },
        "sources": [
            {
                "name": "pypi",
                "url": "https://pypi.org/simple",
                "verify_ssl": true
            }
        ]

python --version Python 3.11.5

Solution

You need to decided whether src is a single package or if it's just a collection of individual modules.

In test_with_pytest, you are using from src import ..., meaning you are treating src as a package. For this you need an __init__.py file.

When running python main.py, and when doing imports like import prompts, you are treating it as if it's just a collection of single-file modules.

You probably should treated it as a single package (and rename the folder something more descriptive/unique than src). Then you would always, in all files, use from src import ... or from src.prompts import ..., and would run it with python -m src.main.

Answered By - MegaIng