Test sum function

Question

Hello everybody all right? First I want to say that it is a pleasure to be part of this community. I’m studying python on my own, I found a course per application, I’m already in the functions part but I didn’t understand the syntax of the command correctly. I would like to do something simple, implement a summation function and a function to test the sum, just for didactic purposes. But my code shows nothing on the screen, follows:

def soma (x, y):
    return (x + y)

def testa_soma():
    if (soma(10, 20) == 30):
        print ('correto')

Answer 1

You have defined two functions one testa_soma and the summing up, but you didn’t call any of them, it should be like this:

def soma (x, y):
    return (x + y)

def testa_soma():
    if (soma(10, 20) == 30):
        print ('correto')

testa_soma()

See that on the last line I put the call.

Answer 2

For a function to be executed, you have to call it:

def soma (x, y):
    return (x + y)

def testa_soma():
    if (soma(10, 20) == 30):
        print ('correto')

testa_soma()

Answer 3

You can also use the module doctest. With it you can create the direct tests on docstring of the function, which centralizes the tests together with the function and assists the documentation of the function.

def soma(x, y):
    """ Retorna a soma de dois números.

    Parâmetros:
        x, y: números a serem somados.

    Retorno:
        Resultado da soma dos números de entrada.

    Exemplos:

    >>> soma(10, 20)
    30
    >>> soma(0, 5)
    5
    >>> soma(-1, -3)
    -4
    >>> soma(-2, 3)
    1
    """
    return x + y

So, in the file, just include:

if __name__ == "__main__":
    import doctest
    doctest.testmod()

And when you run the file, the tests will be checked. If it does not produce any output, it is because all the tests have been successful.