Python Testing

pytest
1. https://docs.pytest.org/en/stable/
2. https://realpython.com/pytest-python-testing/
3. Specifying tests / selecting tests https://docs.pytest.org/en/latest/usage.html#specifying-tests-selecting-tests Pytest supports several ways to run and select tests from the command-line.
  1. Run tests in a module
```
pytest test_mod.py
```
  2. Run tests in a directory
```
pytest testing/
```
  3. Run tests by keyword expressions
```
pytest -k "MyClass and not method"
```
    This will run tests which contain names that match the given string expression, which can include Python operators that use filenames, class names and function names as variables. The example above will run TestMyClass.test_something but not TestMyClass.test_method_simple.
  4. Run tests by node ids Each collected test is assigned a unique nodeid which consist of the module filename followed by specifiers like class names, function names and parameters from parametrization, separated by :: characters.
  5. To run a specific test within a module:
```
pytest test_mod.py::test_func
```
    Another example specifying a test method in the command line:
```
pytest test_mod.py::TestClass::test_method
```
  6. Run tests with print statements
```
pytest -s test_mod.py::TestClass::test_method
```
  7. Run tests with breakpoints
```
pytest -pdb test_mod.py::TestClass::test_method
```
    This will allow you to step through the code with pdb.
  8. Run tests by marker expressions
```
pytest -m slow
```
    Will run all tests which are decorated with the @pytest.mark.slow decorator. For more information see marks.
  9. Run tests from packages
```
pytest --pyargs pkg.testing
```
    This will import pkg.testing and use its filesystem location to find and run tests from.
Debugging
1. https://docs.python.org/3/library/pdb.html
Mocking
1. https://realpython.com/python-mock-library/
unittest
1. https://docs.python.org/3/library/unittest.html

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