Python try except problems

Question

So im having a little trouble with a project im working on. I'm not an expert with Python nor am I an idiot when it comes to coding. This problem may have a very simple answer but I cant seem to get it right. My entire code asks a user to answer questions using a random choice from a list.

    import turtle
import random
turtle.speed("fastest")


pi = 3
minNumber = 5
maxNumber = 10
score = 0
listNmbers = []

a = [1,3,5,7,9]

red = random.random()
green = random.random()
blue = random.random()

num1 = random.choice(a)


def drawSquare():
    for i in range(4):
        turtle.begin_fill()
        turtle.pendown()
        turtle.forward(50)
        turtle.left(90)
        turtle.end_fill()
    turtle.right(360/userAnswer)


turtle.penup()
turtle.setpos(-700,-200)
turtle.fillcolor("green")

print("Welcome! What is your name??")
name = str(input())

print("Hello", name,"you need to calculate the circumference of a circle when given a      diameter. To calculate the circumference, use the equasion; Pi x Diameter (Pi = 3")
num = input("how many questions would you like to answer? (Pick between 5 and 10)")

def getNumbers(numbers):

    try:
        badInput = False
        while not (badInput):
            num = input("how many questions would you like to answer? (Pick between 5 and 10)")
            numbers = int(num)
            badInput = (numbers >= 4) or (numbers >= maxNumber)
            if badInput == False:
                print ("Please input an integer between 5 and 10 please")
                badInput = False
    except:
        print("Please input an integer between 5 and 10")
        numbers= 0;
        numbers = getNumbers(numbers)

numbers= 0;
numbers = getNumbers(numbers)    

for i in range(int(num)):
    red = random.random()
    green = random.random()
    blue = random.random()
    num1 = random.choice(a)
    turtle.color(red,green,blue)
    correct = num1 * 3

    print("What is the cirumference of the circle if", num1,"is the diameter and Pi is 3?")
    userAnswer = int(input())
    if userAnswer == correct:
        print("That's Correct! Well Done")
        score = score + 1

        for k in range(correct):
            turtle.color(red,green,blue)
            drawSquare()

        turtle.penup()
        turtle.forward(150)


    else:
        print("sorry thats is incorrect")

in this bit of code, it asks the user how many questions they want to ask (as an integer). My code works well when a number within the parameters are given, but as soon as a number such as 19 is given, it continues when it should not. Also if a string is given, it works well and asks again for an integer, but if an integer is given after being asked, it crashes. The error read:

for i in range(int(num)):`ValueError: invalid literal for int() with base 10: 'test'`

All help would appreciated so much. thank you all

Answer 1

EDIT: @see xbello answer to have a working answer. My "poisoned" code isn't working as expected ;)

First of all I must say that your code isn't really nice to read... But here are some fixes that should do the trick

maxNumber = 10

print("Hello", name,"you need to calculate the circumference of a circle when given a      diameter. To calculate the circumference, use the equasion; Pi x Diameter (Pi = 3")
num = input("how many questions would you like to answer? (Pick between 5 and 10)")

def getNumbers(numbers):
    try:
        goodInput = False
        while not (goodInput):
            num = input("how many questions would you like to answer? (Pick between 5 and 10)")
            numbers = int(num)

            # Here was a bad condition having a look at your comments
            goodInput = (numbers > 4) and (numbers <= maxNumber)

            if goodInput == False:
                print ("Please input an integer between 5 and 10 please")
                # goodInput is already False, no need to set it again

        # Here is the missing return
        return numbers
    except:
        print("Please input an integer between 5 and 10")
        numbers= 0;
        numbers = getNumbers(numbers)

numbers= 0;
numbers = getNumbers(numbers)    

for i in range(numbers):
    #Do stuff

You can see that I added a return value to your function (that returned None by default) and that I take this return value to push it into "numbers" afterwards. That "numbers" value can then be pushed into a range() function to make a nice for loop.

Answer 2

And you're hidding too much code within a generic try..except (try to Ctrl+C while input is required... nope!). I would write that function in that way:

def getNumbers():

    num = input("how many questions would you like to answer? (Pick between 5 and 10)")
    try:
        number = int(num)
    except:
        print("Not a number!")
        return getNumbers()

    goodInput = minNumber < number < maxNumber

    if not goodInput:
        print ("Please input an integer between 5 and 10 please")
        return getNumbers()
    else:
        return number

number = getNumbers()

Answer 3

getNumbers() doesn't return any value. Thus, it implicitly returns None, which you assign to numbers, here:

numbers = getNumbers(numbers)

Make sure that wherever you exit the getNumbers() function, you return numbers (probably at the end:

def getNumbers(numbers):

   ....

   return numbers