switch implemented with a dictionary

testy.py

def one():
    return "this is function one"

def two():
    return "this is function two"

def three():
    return "this is function three"


def demo(argument):

    switcher = {
        1: one,
        2: two,
        3: three
    }

    # Get the function from the switcher dictionary
    # Two bits of python capability here
    # 1. Lambda
    #   lambda is small anonymous function.
    #
    #   Example:
    #       return lambda a, b: a+b
    #
    # 2. dictionary get method
    #   Similar to some_dict[a_key], returns a default value if key is not found.
    #
    #   Example:
    #       some_dict.get(a_key, default_value) 
    #
    func = switcher.get(argument, lambda: "Invalid argument")
    # execute the function
    print(func())

demo(1)
demo(2)
demo(3)
demo(4)

testy2.py

def one(a_param):
    print("This is function one")
    print("This is a parameter {}" . format(a_param))
    return 

def two(a_param):
    print("This is function two")
    print("This is a parameter {}" . format(a_param))
    return 

def three(a_param):
    print("This is function three")
    print("This is a parameter {}" . format(a_param))
    return 


def demo(argument):

    switcher = {
        1: one,
        2: two,
        3: three
    }

    # Get the function from the switcher dictionary
    # Two bits of python capability here
    # 1. Lambda
    #   lambda is small anonymous function.
    #
    #   Example:
    #       return lambda a, b: a+b
    #
    # 2. dictionary get method
    #   Similar to some_dict[a_key], returns a default value if key is not found.
    #
    #   Example:
    #       some_dict.get(a_key, default_value) 
    #
    a_param = "123"
    func = switcher.get(argument, lambda x: print("Invalid argument " + x) )
    # execute the function
    func(a_param)

demo(1)
demo(2)
demo(3)
demo(4)