What does def method (parameter = None) mean? [closed]

Question

class Employee:
    def __init__(self, lastname, firstname = None):
        self.lastname = lastname
        self.firstname = firstname

What does firstname = None in the second row mean?

Answer 1

This allows you to call this function and omit that particular parameter. If you do omit it, it will default to the listed value of None. If you do pass a value, it will be used.

>>> def f(arg='a'):
...     print(arg)
...
>>> f()
a
>>> f('b')
b