pytest-regex

0.2.0 · active · verified Thu Apr 16

pytest-regex is a pytest plugin that allows users to select tests for execution using regular expressions against the full test node ID. It extends pytest's test selection capabilities beyond keyword (`-k`) and marker (`-m`) expressions. The current version is 0.2.0, and it maintains an infrequent release cadence.

Common errors

```
pytest: error: unrecognized arguments: --regex
```
cause The `pytest-regex` plugin is not installed or not accessible to pytest in your current environment.

fix Ensure the plugin is installed using `pip install pytest-regex` within the active virtual environment where you run `pytest`.
```
============================= no tests ran in X.YZs =============================
```
cause The regular expression provided with `--regex` did not match any of the collected test node IDs, or was too restrictive.

fix Verify your regex pattern is correct and matches your test node IDs. Use `pytest --collect-only` to inspect the full list of collected test node IDs and refine your regex accordingly. Consider if other filters (`-k`, `-m`) are also contributing to the problem.

Warnings

gotcha The `--regex` flag matches against the *full test node ID*, which includes the file path, module, class, and function name (e.g., `test_module.py::TestClass::test_method`). Simple patterns like `test_my_func` might not match if the full path isn't considered.
Fix: Ensure your regex pattern accounts for the full test node ID. Use `pytest --collect-only` to see the full node IDs before constructing complex patterns.
gotcha pytest-regex functionality is exclusively exposed via command-line arguments (`--regex` and `--regex-file`). There is no public Python API for direct programmatic interaction with the plugin's regex matching logic.
Fix: Use `subprocess` to call `pytest` with the desired command-line arguments if programmatic execution with regex filtering is required.
gotcha When combining `--regex` with other selection options like `-k` (keyword) or `-m` (marker), pytest typically applies all filters. An overly restrictive combination of filters can lead to 'No tests ran'.
Fix: Start with only the `--regex` filter to confirm your pattern works, then gradually add other filters. If no tests are collected, try removing filters one by one to isolate the issue.

Install

pip install pytest-regex Install plugin

Imports

pytest-regex
```
This library is a pytest plugin; its functionality is accessed via the `pytest` command-line interface, not through direct Python imports.
```
Users do not import symbols from `pytest_regex` directly. The plugin integrates with pytest's test collection and selection mechanisms.

Quickstart

Create a `test_example.py` file with some tests. Then, install `pytest` and `pytest-regex`. Run pytest from the command line using the `--regex` flag to filter tests based on a regular expression matching the full test node ID (e.g., `test_example.py::test_add`).

import pytest

# test_example.py
def test_add():
    assert 1 + 1 == 2

def test_subtract():
    assert 2 - 1 == 1

class TestMathOperations:
    def test_multiply(self):
        assert 2 * 2 == 4

# To run: save the above as 'test_example.py'
# Then run from your terminal:
# pip install pytest pytest-regex
# pytest --regex "test_add"
# pytest --regex "TestMathOperations::test_multiply"
# pytest --regex "^(test_add|test_subtract)$"

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