personal_bot

def char_checker(a):
    if a.isdigit() == False or not a:
        return False
    else:
        return True

def zero_checker(a):
    if int(a) == 0:
        return False
    else:
        return True

def do_calculation():
    while True:
        num1 = input("Enter first number: ")
        num2 = input("Enter second number: ")
        if opr == "add" or opr == "Add" or opr == "+":
            if char_checker(num1) == False or char_checker(num2) == False:
                print("Not acceptable! Enter again")
                continue
            else:
                result = int(num1) + int(num2)
                output = str(result)
        elif opr == "substract" or opr == "Substract" or opr == "-":
            if char_checker(num1) == False or char_checker(num2) == False:
                print("Not acceptable! Enter again")
                continue
            else:
                result = int(num1) - int(num2)
                output = str(result)
        elif opr == "multiply" or opr == "Multiply" or opr == "*":
            if char_checker(num1) == False or char_checker(num2) == False:
                print("Not acceptable! Enter again")
                continue
            else:
                result = int(num1) * int(num2)
                output = str(result)
        elif opr == "divide" or opr == "Divide" or opr == "/":
            if char_checker(num1) == False or zero_checker(num2) == False or char_checker(num2) == False:
                print("Not acceptable! Enter again")
                continue
            else:
                result = int(num1) / int(num2)
                output = str(result)
        if opr == "add" or opr == "Add" or opr == "+":
            print(num1 + "+" + num2 + "=" + output)
            break
        elif opr == "substract" or opr == "Substract" or opr == "-":
            print(num1 + "-" + num2 + "=" + output)
            break
        elif opr == "multiply" or opr == "Multiply" or opr == "*":
            print(num1 + "*" + num2 + "=" + output)
            break
        elif opr == "divide" or opr == "Divide" or opr == "/":
            print(num1 + "/" + num2 + "=" + output)
            break

print("Hi, I'm Marvin, your personal assistant.")
your_name = input("What's your name?\n")
print("Welcome " + your_name + "!")
while True:
    print()
    opr = input("I can add[+], substract[-], multiply[*], divide[/] and [a]verage calculations and [s]hopping list generation.\nWhich one do you need?\n")
    if opr == "add" or opr =="+" or opr == "substract" or opr == "-" or opr == "multiply" or opr == "*" or opr == "divide" or opr == "/":
        do_calculation()
        continue

    while True:
        if opr == "a" or opr == "A":
            how_many = input("How many numbers do you want to calculate?\n")
            total = 0
            for number_count in range(int(how_many)):
                number = input("Enter number " + str(number_count) + ": ")
                total = total + int(number)
            avr = total/int(how_many)
            print()
            print("The average of the " + how_many + " numbers you entered is: " + str(avr))
            break
        elif opr == "s" or opr == "S":
            how_many = input("How many items do you want to buy? : ")
            shopping = []
            total = 0
            for item_count in range(int(how_many)):
                item = input("What is the item " + str(item_count) + " you want? : ")
                price = float(input("What is the price for this item? : "))
                shopping.append(item)
                total = total + price
            print()
            for item in shopping:
                print(item)
            if int(how_many) > 1:
                print()
                print("You have " + str(len(shopping)) + " items in your shopping list.\nTotal price of these items are " + str(total) + " $")
                break
            else:
                print()
                print("You have " + str(len(shopping)) + " item in your shopping list.\nTotal price of these items are " + str(total) + " $")
                break
        else:
            print()
            print("I'm not capable of doing " + opr + " at the moment. You should keep upgrading me.")
            break
    continue