After the split x becomes (1 and z becomes 1). They can’t be converted to float. I think that’s why. Let me run the code. Edit - Also as you are returning a, b, c from splitter but Python functions return a single object. The a, b, c turns to a tuple. But you are using js syntax I think. So we have to unwrap inside the calculate function.

Now my original comment is not useful but you can try to introduce a conditional to check of the numbers x and z are actually numbers before converting to floats

# Ask user to enter an expression and display output

def main():
    expression = input("Expression: ")
    print(calculate (splitter (expression)))

# Split expression into components and assign to variables as float values

def splitter (expression):
    print(expression)
    x, y, z = expression.split()
    print(expression.split())
    return x, y, z

# Calculate expression result

# Changes Beginning
def calculate(numbers):
    x,y,z = numbers
# Changes End

    x, z = float(x), float(z)
    if y == "+":
        return str(round((x + z), 1))
    elif y == "-":
        return str(round((xz), 1))
    elif y == "*":
        return str(round((x*z), 1))
    else:
        return str(round((x / z), 1))

main()

Waiting for a youtube iceberg video to mention this incident

I knew that so coordinate are for my college not my residence

Sorry I will work on it. Thank you

Nice to have you Karna. Welcome to lemmy. But you have posted on c\news which is a community for world news and not for new users introduction. As you are involved in Audio, Engineering and Artists you can find other communities which better suit your preference. Also you can find community based on location like Sydney and Australia . As this post is in wrong community I would have to down vote your post. But you are free to checkout other relevant communites and post there.

Hope you enjoy lemmy.😊👋