Doctest

Das Python-Modul doctest prüft, ob Tests in einem Docstring oder in einer anderen Textdatei erfüllt sind.

  1. In arithmetic.py könnt ihr folgenden Docstring hinzufügen:

     9def divide(x, y):
10    """Divides the first parameter by the second
11    >>> x, y, z = 7, -6.0, 0
12    >>> round(divide(x, y), 8)
13    -1.16666667
14    >>> divide(x, z)
15    Traceback (most recent call last):
16      File "<stdin>", line 1, in <module>
17    ZeroDivisionError: division by zero
18    """
19    return x / y

  2. Anschließend könnt ihr ihn testen mit:

    $ python -m doctest test/arithmetic.py -v
Trying:
    add(7,6)
Expecting:
    13
ok
Trying:
    x, y, z = 7, -6.0, 0
Expecting nothing
ok
Trying:
    round(divide(x, y), 8)
Expecting:
    -1.16666667
ok
Trying:
    divide(x, y)
Expecting:
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    ZeroDivisionError: division by zero
ok
Trying:
    multiply(7,6)
Expecting:
    42
ok
Trying:
    subtract(7,6)
Expecting:
    1
ok
1 items had no tests:
    arithmetic
4 items passed all tests:
   1 tests in arithmetic.add
   3 tests in arithmetic.divide
   1 tests in arithmetic.multiply
   1 tests in arithmetic.subtract
6 tests in 5 items.
6 passed and 0 failed.
Test passed.

    C:> python -m doctest arithmetic.py -v
Trying:
    add(7,6)
Expecting:
    13
ok
Trying:
    x, y, z = 7, -6.0, 0
Expecting nothing
ok
Trying:
    round(divide(x, y), 8)
Expecting:
    -1.16666667
ok
Trying:
    divide(x, y)
Expecting:
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    ZeroDivisionError: division by zero
ok
Trying:
    multiply(7,6)
Expecting:
    42
ok
Trying:
    subtract(7,6)
Expecting:
    1
ok
1 items had no tests:
    arithmetic
4 items passed all tests:
   1 tests in arithmetic.add
   3 tests in arithmetic.divide
   1 tests in arithmetic.multiply
   1 tests in arithmetic.subtract
6 tests in 5 items.
6 passed and 0 failed.
Test passed.

  3. Damit die Doctests auch in andere Module importiert werden können, solltet ihr die folgenden Zeilen hinzufügen:

    38if __name__ == "__main__":
39    import doctest
40
41    doctest.testmod(verbose=True)

Siehe auch

doctest kann auch zum kontinuierlichen Testen der Dokumentation verwendet werden: Kontinuierliche Integration.