how to make a calculator using python

                                    #no gui

def  add(a,b):
    result=a+b
    print(result)

def sub(a,b):
    resulf=a-b
    print(resulf)

def mul(a,b):
    resulf=a*b
    print(resulf)

def div(a,b):
    resulf=a/b
    print(resulf)

a=int(input("enter th first number: "))
b=int(input("enter th second number: "))
op=input("enter the sign: ")

if op=="+":
    add(a,b)

elif op=="-":
    sub(a,b)    

elif op=="*":
    mul(a,b)  

elif op=="/":
    div(a,b)    

else:
    print("invalid")

                                    #You can change Text at Inputs

num1 = float(input("Enter Firt Number:"))
num2 = float(input("Enter Second Number"))

result= 0
op = str(input("Enter an op(operator)"))
#Gets Input Type--------
try:
  #U can make this in while loop ;-)
  if op=="+":
    result = num1 + num2
  else if op=="-":
    result = num1 - num2
  else if op=="*":
    result = num1 * num2
  else if op=="/":
    result = num1 / num2
  else:
      print("Invalid Input")
  print("The result is " + result)
except ZeroDivisionError:
  print("U cant do that")

                                    def add(num1, num2):
    return num1 + num2

def subtract(num1, num2):
    return num1 - num2

def multiply(num1, num2):
    return num1 * num2

def divide(num1, num2):
    return num1 / num2

                                    
# Define variables for number inputs..
num1 = int(input("Enter first number: "))
num2 = int(input("Enter second number: "))

# Input for operators
op = input("Enter operator: ")

# Functions for operations


def add(num1, num2):
    print('Result: ', num1 + num2)


def subtract(num1, num2):
    print('Result: ', num1 - num2)


def multiply(num1, num2):
    print('Result: ', num1 * num2)


def division(num1, num2):
    print('Result: ', num1 / num2)


# Using the functions
if op == '+':
    add(num1=num1, num2=num2)
elif op == '-':
    subtract(num1=num1, num2=num2)
elif op == '*':
    multiply(num1=num1, num2=num2)
elif op == '/':
    division(num1=num1, num2=num2)
else:
    print('Invalid operator')

                                    #My Personal Python calculator
print("My Personal Python calculator")
#inputs
num1 = int(input('Enter the first number:  '))
num2 = int(input('Enter the second number:  '))
#opration req
opr = input('Enter the type of operation you want to perform between your chosen two numbers:  ')
#calculation
if opr=='+':
    ans = num1 + num2
    # displaying the answer
    print(f'Your final answer is {ans}')
elif opr == '- ':
    ans = num1 - num2
    # displaying the answer
    print(f'Your final answer is {ans}')
elif opr=='*':
    ans = num1 * num2;
    # displaying the answer
    print(f'Your final answer is {ans}')
elif opr=='/':
    ans = num1 / num2
    # displaying the answer
    print(f'Your final answer is {ans}')
else:
    print('Invalid Entry!!!')