Is it possible in Python to make multilevel if / how to make a puzzle with Stepik calculator?

Question

Python

b = float(input())
x = input()
if x == "+" :
 print(a+b)
elif x =="-" :
 print(a-b)
elif x =="*" :
 print(a*b)
elif x =="pow" :
 print(a**b)
elif x=='/':
    if b=='0':
     print('Деление на 0!')
    else:
     print(a/b)
elif x=='mod':
    if b=='0':
     print('Деление на 0!')
    else:
      print(a//b)
elif x=='div':
    if b=='0':
     print('Деление на 0!')
    else:
     print(a%b)
# не робит це

a = float(input())

Answer 1

def calc(a,b,op):
    if op in ['/', 'mod', 'div'] and b == 0:
        return 'Деление на 0!'
    else:
        return({
              '+': a+b,
              '-': a-b,
              '*': a*b,
              '/': a/b,
              'mod': a//b,
              'div': a%b,
            }.get(op, 'Неизвестная операция!'))

print(calc(1,2,'+'))
print(calc(1,2,'/'))
print(calc(2,0,'mod'))
print(calc(0,2,'$'))

3
0.5
Деление на 0!
Неизвестная операция!

Answer 2

yes, but i would do that

import operator

action = {
    "+": operator.add,
    "-": operator.sub,
    "/": operator.truediv,
    "*": operator.mul,
    "**": operator.pow
    }
# .....

b = float(input())
a = float(input())
x = input()
act= action.get(x, None)
if act:
   try:
     answer = act(a, b)
   except  ZeroDivisionError as e:
       print(u"Деление на 0!")
   else:
     print(answer)

Answer 3

def addition(a, b):
    return a + b

def subtraction(a, b):
    return a - b

operations = {
    '+': addition,
    '-': subtraction
}

print(operations['+'](5, 7));
print(operations['-'](9, 4));