Default Parameter Values

Sometimes it is useful to set a default value for a parameter, for example when the parameter value is often repeated. 

Default parameter values allow us to call the function without having to provide all parameter values. If a value is not provided for a parameter with a default value, the default value is used. We specify the default value of a parameter during the function definition using the = operator. For example:

def greet(name="world"):
    print("Hello, " + name)

This function has one parameter name with a default value "world". When we call the function without an argument:

greet() # Outputs: Hello, world

The function uses the default value and prints Hello, world.

When we call the function with an argument:

greet("Karel") # Outputs: Hello, Karel

The function uses the provided value and prints Hello, Karel.