Python 3: While loop not returning False

Question

I'm making a 3 in a row game for practice using the concepts I have learned in class so far: while loops, booleans, and if-statements.

For some reason, my function doesn't seem to be returning False even though I give an argument in which it should. Instead I get a 'executing command, please wait for result' message, where nothing comes up after that. Initially I thought it was caught in an infinite loop somewhere, but I don't think it should as I gave limits to all my variables and added the +=1 at the end for all of the while loops.

Any help will be much appreciated!

Here is a snippet of my code below:

def is_winner(grid):
 x = 0
 y = 0
 while x <=3:
 x +=1
 while y <= 4: 
 if grid[x][y] == grid[x + 1][y] ==grid[x + 2][y]:
 y += 1
 return True
 while x <= 3: 
 x +=1
 while y <= 3:
 if grid[x][y] == grid[x + 1][y - 1] == grid[x + 2][y - 2]:
 y +=1
 return True
 else:
 return False

Answer 1

You only ever increment y if the if statements are True. If they never are, you entered into an infinite loop:

while x <=3:
 while y <= 4: 
 x +=1
 if grid[x][y] == grid[x + 1][y] ==grid[x + 2][y]]:
 y += 1

Your inner while loop never completes, so your outer while loop is never tested.

Change this to:

while x <=3 and y <= 4: 
 x +=1
 if grid[x][y] == grid[x + 1][y] ==grid[x + 2][y]]:
 y += 1

• muros: Oh ho! You're my hero! Thank you :)
• muros: Quick question. To use [x][y] like (x, y) coordinates, do I need to import math or something? I keep getting string index out of range.
• Martijn Pieters: If your grid list contains other lists, then using grid[x] refers to an index in the outer list, and the [y] part then applies to that returned value, also a list. If you get string index errors, then either grid is a string itself or it is a list where at least one of its values is a string.