Question

http://pastie.org/1966237

I keep getting an unbound local error. I don’t understand why it occurs, if the program is running right, it should go straight into the second assignment of the print_et_list function within the main function, looping itself without actually looping. The program only quits using sys.exit() in the hey_user function.

I included the whole program for context, it isn’t too long. Let me know if you want to have a look at the text files I use in the program, however I’m sure it’s unlikely that it is the source of the problem.

Answer 1

UnboundLocalError happens when you read the value of a local variable before you set it. Why is score a local variable rather than a global variable? Because you set it in the function. Consider these two functions:

def foo():
    print a

vs

def bar():
    a = 1
    print a

In foo(), a is global, because it is not set inside the function. In bar(), a is local. Now consider this code:

def baz():
    print a
    a = 1

Here, a is set within the function, so it’s local. But it hasn’t been set at the time of the print statement, so you get the UnboundLocalError.