4.9 Default Parameter Values

  • You can specify that a parameter has a default parameter value.
  • When calling the function, if you omit the argument for a parameter with a default parameter value, the default value for that parameter is automatically passed.
In [1]:
def rectangle_area(length=2, width=3):
    """Return a rectangle's area."""
    return length * width
  • Specify a default parameter value by following a parameter’s name with an = and a value.
  • Any parameters with default parameter values must appear in the parameter list to the right of parameters that do not have defaults.
In [2]:
rectangle_area()
Out[2]:
6
In [3]:
rectangle_area(10)
Out[3]:
30
In [4]:
rectangle_area(10, 5)
Out[4]:
50
In [ ]:
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