Thread by @driscollis

Let's take some time and learn about testing in #Python today.

To kick things off, you'll learn about the `doctest` module!

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What is `doctest`? #Python's `doctest` modules looks for pieces of text in docstrings that look like REPL sessions.

Next, it executes them and verifies that the output in the docstring matches when the code is actually run

Check out the docs: docs.python.org/3/library/doct…

Here is an example of a #Python function with a docstring that could be used by the `doctest` module to test that function:

You call the `doctest` module with #Python by using the `-m` flag with the Python executable

If you call `doctest` without any flags, it will only show output if there is an error in the test

If you pass `-v` to `doctest`, then you run it in verbose mode

Here are a couple of runs of that code above. The file was named `dtest.py` for this example.

You run it once without `-v` and then again with `-v`. Check out the output to see what happens

You can also run `doctest` within the module instead of calling the #Python executable directly.

To do that, `import doctest` and then run `testmod()`:

All of the examples in this thread come from my article on `doctest` over on @mousevspython here:

blog.pythonlibrary.org/2014/03/17/pyt…

I hope you enjoyed learning about basic testing in #Python with `doctest`

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