Assign a global Array in Python

Question

I found a project to learn Python: Tetris My plan was to assign a global Array in a variable() function to clean up my main() function.

but i get a syntax error

def globalv():
    global x
    x = 40
    global y
    y = 10
    global Tetris[40][10]
    for x in 40:
        for y in 10:
            Tetris[x][y] = 0

def main():
    globalv()

if __name__ == "__main__":
    main()

I don't know what i'm doing wrong Thank you