name 'times' is used prior to global declaration - But IT IS declared!

Question

I\'m coding a small program to time and show, in a ordered fashion, my Rubik\'s cube solvings. But Python (3) keeps bothering me about times being used prior to global decla

Answer 1

The global declaration is when you declare that times is global

def timeit():
    global times # <- global declaration
    # ...

If a variable is declared global, it can't be used before the declaration.

In this case, I don't think you need the declaration at all, because you're not assigning to times, just modifying it.

Answer 2

From the Python Docs

Names listed in a global statement must not be used in the same code block textually preceding that global statement.

Answer 3

From the Python documentation:

Names listed in a global statement must not be used in the same code block textually preceding that global statement.

https://docs.python.org/reference/simple_stmts.html#global

So moving global times to the top of the function should fix it.

But, you should try not to use global in this situation. Consider using a class.

Answer 4

For the main program, you can declare it on the top. Ther will be no warning. But, as said, the global mention is not useful here. Each variable put in the main program is in the global space. In functions, you must declare that you want use the global space for it with this keyword.

Answer 5

This program should work but may not work exactly as you intended. Please take note of the changes.

import time

times = []

def timeit():
    input("Press ENTER to start: ")
    start_time = time.time()
    input("Press ENTER to stop: ")
    end_time = time.time()
    the_time = round(end_time - start_time, 2)
    print(str(the_time))
    times.append(the_time)

def main():
    while True:
        print ("Do you want to...")
        print ("1. Time your solving")
        print ("2. See your solvings")
        dothis = input(":: ")
        if dothis == "1":
            timeit()
        elif dothis == "2":
            sorted_times = sorted(times)
            sorted_times.reverse()
            for curr_time in sorted_times:
                print("%d - %f" % ((sorted_times.index(curr_time)+1), curr_time))
            break
        else:
            print ("WTF? Please enter a valid number...")

main()