I don't really have an exercise that I'm stuck at, but I do have a concept that I can't seem to understand. For example (taking an example from the exercise):
board = 
for i in range(0,5):
board.append(["O"] * 5)
There is no instance of "i" anywhere else except right before the range. Why isn't there a syntax error (Something like NameError: name 'i' is not defined)? How does "i" just implied to be a variable that is a placeholder?
Thank you in advance!