Get ingredient amount and scale it

05_scale_ingredients.py

# Ingredients list


# Number Checking Function
def num_check(question):
    error = "Please enter a number that is more than zero"

    valid = False
    while not valid:
        try:
            response = float(input(question))

            if response <= 0:
                print(error)
            else:
                return response

        except ValueError:
            print(error)

# Not blank function goes here
def not_blank(question, error_msg, num_ok):
    error = error_msg

    valid = False
    while not valid:
        response = input(question)
        has_errors = ""

        if num_ok != "yes":
            # look at each character in string and if it's a number, complain
            for letter in response:
                if letter.isdigit() == True:
                    has_errors = "yes"
                    break

        if response == "":
            print(error)
            continue
        elif has_errors != "":
            print(error)
            continue
        else:
            return response

# Main Routine...

# Replace line below with component 3 in due course...
scale_factor = float(input("Scale Factor: "))

# Set up an empty ingredients list
ingredients = []

# Loop to ask users to enter an ingredient
stop = ""
while stop != "x":

    amount = num_check("What is the amount for the ingredient? ")
    scaled = amount * scale_factor

    # Ask user for ingredient (via not blank function)
    get_ingredients = not_blank("Please type in an ingredient name: ", "This can't be blank", "yes")

    # Stop looping If exit code is typed and there are more than 2 ingredients...
    if get_ingredients.lower() == "x" and len(ingredients) > 1:
        break

    elif get_ingredients.lower() == "x" and len(ingredients) < 2:
        print("You need at least two ingredients in this list.  Please add more ingredients.")

    # If exit code is not entered, add ingredients to list
    else:
        ingredients.append(get_ingredients)

# Output list
print(ingredients)