Crea una calculadora que sume reste multiplique y divida

def calc(a, b, op):
  if op == "+":
    return a + b
  elif op == "-":
    return a - b
  elif op == "*":
    return a * b
  elif op == "/":
    return a / b
  else:
    return "Not a valid operation"

calc(5, 10, "+")