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Default values

In some cases, it is convenient to have a default value for a specific argument, so that we won't need to state it explicitly every time. For example, we can assume that most of the time, we need to get a negative square root (depending on the case, of course), and it would be a waste of time to explicitly define p=2 every time. In this case, we'll have to modify our code just a bit, by p=2 within the parentheses. Here is how the code would appear:

def negative_power(v, p=2):    ‘''Return negative value v in power p'''    return -1 * (v**p)

We still have to define v every time, but p is now optional – if we don't state it explicitly, it will be assumed to be equal to 2. The following code illustrates the case. Once we don't explicitly ...