How to make a calculator function that uses the operator as an input?

I started learning Python yesterday; this is the first calculator I’ve made. I noticed that the last lines of code that print the equation’s result are repeated.

Can I write a function that takes the operator as input and then prints the result with just one line of code?

I imagine it would be something like this:

def result(operator):

print((str(num1)) + ” ” + str(operator) + ” ” + str(num2) + ” = ” + str(num1 insert operator to compute equation num2))

    num1 = float(input("Enter first number: "))

    op = None
    while op not in ("-", "+", "*", "/"):
        op = input("Enter operator (-, +, *, /):  ")

    num2 = float(input("Enter second number: "))

    if op == "-":
      print((str(num1)) + " " + str(op) + " " + str(num2) + " = " + str(num1 - num2))
    elif op == "+":
      print((str(num1)) + " " + str(op) + " " + str(num2) + " = " + str(num1 + num2))
    elif op == "*":
      print((str(num1)) + " " + str(op) + " " + str(num2) + " = " + str(num1 * num2))
    elif op == "/":
      print((str(num1)) + " " + str(op) + " " + str(num2) + " = " + str(num1 / num2))

Answer

You might try using a dictionary to map strings (operators) to function objects:

from operator import add, sub, mul, floordiv

operations = {
    "+": add,
    "-": sub,
    "*": mul,
    "/": floordiv
}

a = float(input("Enter first number: "))

while (op := input("Enter operator: ")) not in operations: pass

# 'operation' is one of the four functions - the one 'op' mapped to.
operation = operations[op]

b = float(input("Enter second number: "))

# perform whatever operation 'op' mapped to.
result = operation(a, b)

print(f"{a} {op} {b} = {result}")

In this case, add, sub, mul and floordiv are the function objects, each of which take two parameters, and return a number.