7 kyu Make a function that does arithmetic!.py

"""
https://www.codewars.com/kata/583f158ea20cfcbeb400000a/train/python

Given two numbers and an arithmetic operator (the name of it, as a string), return the result of the two numbers having that operator used on them.

a and b will both be positive integers, and a will always be the first number in the operation, and b always the second.

The four operators are "add", "subtract", "divide", "multiply".

A few examples:

arithmetic(5, 2, "add")      => returns 7
arithmetic(5, 2, "subtract") => returns 3
arithmetic(5, 2, "multiply") => returns 10
arithmetic(5, 2, "divide")   => returns 2.5

ArithmeticFunction.arithmetic(5, 2, "add")      => returns 7
ArithmeticFunction.arithmetic(5, 2, "subtract") => returns 3
ArithmeticFunction.arithmetic(5, 2, "multiply") => returns 10
ArithmeticFunction.arithmetic(5, 2, "divide")   => returns 2

Try to do it without using if statements!
"""


def arithmetic(a, b, operator):
    def add():
        return a + b
    
    
    def subtract():
        return a - b


    def multiply():
        return a * b


    def divide():
        return a / b
    
    
    method = {
    "add": add,
    "subtract": subtract,
    "multiply": multiply,
    "divide": divide
    }
    
    return method[operator]()
  
  
  # very proud of myself, coz no 'if-else'
    
   
    # more compact:
    
#     def arithmetic(a, b, operator):
#     return {
#         'add': a + b,
#         'subtract': a - b,
#         'multiply': a * b,
#         'divide': a / b,
#     }[operator]