Assigning and Calling built-in functions from a dictionary Python

Assigning and Calling built-in functions from a dictionary Python

Method #1:

Use operator.methodcaller

from operator import methodcaller


commands = {"1": methodcaller('upper'),
            "2": methodcaller('lower'),
            "3": methodcaller('replace', " ", "\n")}

user_string = input("Enter a string: ")
option = input("How would you like to alter your string? (Choose one of the following:)\
\t1. Make all characters capital\
\t2. Make all characters lowercase")

result = commands[option](user_string)

Method #2:

commands = {"1" : str.upper, "2" : str.lower, "3" : lambda string: str.replace(string, " ", "\n")}  # use a lambda here to pass extra parameters

user_string = input("Enter a string: ")
option = input("How would you like to alter your string? (Choose one of the following:)\
\t1. Make all characters capital\
\t2. Make all characters lowercase")

new_string = commands[option](user_string)

Method #3:

command = lambda a:{"1" : a.upper(), "2" : a.lower(), "3" : a.replace(" ",'\n')}

user_string = input("Enter a string: ")
options = input("How would you like to alter your string? (Choose one of the following:)")
print("output:",command(user_string)[options])
#\t1. Make all characters capital\n