whats wrong with this code?

Question

the code should, in the end, output the result of the operation but, it isn't even recognizing the operations correctly and, the sum, "auto-related" itself to simple_calculator

import time

greatings = ("\n Hi! Welcome to program test_1")
print(greatings)

def program_delay(x, y):
time.sleep(y)
print(x)

text_1 = ("\n «ATENTION» The program is ready to load")
program_delay(text_1, 5)

are_you_sure = ("\n Are you sure that you want the program to be loaded?")
program_delay(are_you_sure, 4)

yes_or_no = input("»( y / n ): ")

yes = ("y")
no = ("n")

program_start = ("\n Loading Program ...")

if yes_or_no == yes:
program_delay(program_start, 1)

def loading(x):
for i in range(101):
time.sleep(x)
i = "»" + str(i) + "%"
print(i)

loading(0.5)

print("\n")

comands = input("root /project_1 /program test_1 >")

print("\n")

def simple_calculator(z, e):
return e
x = int(x)
y = int(y)
sum = x + y
div = x / y
sub = x - y
mp = x * y
if z == "sum":
print(sum)
elif z == "div":
print(div)
elif z == "mp":
print(mp)
elif z == "sub":
print(sub)
else:
print("unknown comand, please try again")

def calculator_extra():
x = input("Choose the fist number: ")
y = input("Choose the second number: ")

if comands == "smpl calc":
loading(0)
if comands == "smpl calc":
z = input("Choose an operation type: ")
if comands == "smpl calc":
simple_calculator( z, calculator_extra())
else:
print("Unknown process")

Answer 1

first get rid of all delays
after... step by step

Answer 2

yes... good job!

Answer 3

Thanks, now it's working at 100%, even with the delays (I removed them and added them again after solving the problem)