how to set a default parameter in python

1def my_function(name, age = 20):
2  print(name + " is " + str(age) + " years old"
3
4my_function("Mitro") # Mitro is 20 years old
5my_function("Mitro", 26) #Mitro is 26 years old

1def my_function(num1,num2=0):		#if num2 is not given, it will default it to zero
2  return num1 + num2
3
4print(my_function(1,2))				#prints out 3
5print(my_function(4))				#prints out 4 since num2 got defaulted to 0

1def your_function(arg,kwarg='default'):
2    return arg + kwarg

1class Test:
2    def __init__(self, val, num = 0):
3        self.val = val
4        self.num = num
5
6# you can write this:
7
8t = Test(1)
9print(t.num) # prints 0
10
11# OR this
12
13t = Test(1, 2)
14print(t.num) # prints 2