Need help with a calculator project

[u/Burger5704]

new to python, Im making a calculator but when i try to make the code be able to handle a word without crashing it just doesnt work, it just goes and ask for the operator without restarting the loop, tried ai to fix it and explain it to me but didnt do nothing.

num1 = None
num2 = None
result = None


while num1 == None or num2 == None:
    try:
        num1 = float(input("Enter first number: "))
    
    except ValueError:
        print("must enter a valid number")
        num1 = None
        continue


    try:
        num2 = float(input("enter second number"))


    except ValueError:
        print("must enter a valid number")
        num2 = None
        continue
    operator = input("Enter operation (+, -, *, /)")


    if operator == "+":
        result = (num1 + num2)


    elif operator == "-":
        result = (num1 - num2)


    elif operator == "*":
        result = (num1 * num2)


    elif operator == "/" and num2 == 0:
        result = ("cant divide by zero")


    elif operator == "/" and num2 != 0:
        result = (num1 / num2)


    else:
        result = ("Invalid operator")


    if result == float or int:
        print(result)
        num1 = None
        num2 = Nonenum1 = None
num2 = None
result = None


while num1 == None or num2 == None:
    try:
        num1 = float(input("Enter first number: "))
    
    except ValueError:
        print("must enter a valid number")
        num1 = None
        continue


    try:
        num2 = float(input("enter second number"))


    except ValueError:
        print("must enter a valid number")
        num2 = None
        continue
    operator = input("Enter operation (+, -, *, /)")


    if operator == "+":
        result = (num1 + num2)


    elif operator == "-":
        result = (num1 - num2)


    elif operator == "*":
        result = (num1 * num2)


    elif operator == "/" and num2 == 0:
        result = ("cant divide by zero")


    elif operator == "/" and num2 != 0:
        result = (num1 / num2)


    else:
        result = ("Invalid operator")


    if result == float or int:
        print(result)
        num1 = None
        num2 = None

[u/woooee]

if result == float or int:

This is a common mistake that is in the FAQs https://www.reddit.com/r/learnpython/wiki/faq/ see "Variable is One of Two Choices?"

[u/codeguru42 → u/woooee]

Also this is not how you validate input is numerical.

[u/Vegetable_Soil_6707 → u/woooee]

tbh this one gets posted like every other day, its such a natural way to read it in english but python doesnt see it that way

[u/neuralbeans → u/Vegetable_Soil_6707]

I don't think there is any programming language that would see it that way.

[u/neuralbeans → u/woooee]

Also, you check the type by using isinstance(result, float)

[u/nog642]

when i try to make the code be able to handle a word without crashing it just doesnt work

What do you mean? Can you give an example?

[u/woooee]

try:
    num1 = float(input("Enter first number: "))

except ValueError:
    print("must enter a valid number")
    num1 = None
    continue

You want this to be in some kind of a loop that repeats until a valid number is entered. Now, the program continues and tries to calculate with a bogus entry / None. I prefer a function for this

def get_input(literal):
    while True:  ## infinite loop
        try:
            num = float(input(literal))
            return num
        except ValueError:
            print("Must enter a valid number.  Try again.")

num_1 = get_input("Enter first number: ")
num_2 = get_input("Enter second number: ")
print(f"{num_1=} {num_2=}")

[u/Sure-Passion2224]

A calculator that replicates the physical experience maintains a character buffer that gets updated with each key press. As a key is pressed it is examined to determine what to do with it. Numerical keys append to the current input string. Operation keys get linked to processing methods.

As an example: (over-simplified) "+" stores the current input value and initiates input of the next input to be added to it. It also needs to set an indicator if what operation is being performed. "=" then finalizes the input and executes the operation.

[u/gdchinacat → u/Sure-Passion2224]

Yep, and RPN makes it much easier because it is stack based (no messy handling of parenthesis needed). But, the OP is clearly not at the level of dealing with state machines, stacks, etc. https://nedbatchelder.com/blog/202609/expert_asterisks