Naughts and Crosses win check

[GalaxyCoyote]

I was wondering how I would make a Win checker for my Naughts and Crosses game (Tic Tac Toe).

I am using lists

Row1 = ["-","-","-"] 
Row2 = ["-","-","-"] 
Row3 = ["-","-","-"]

Loop = True #Loop
Turn = 0 #Flips between Player 1 and Player 2
Pinput = 0 #Player input

def check():
    print("checkerhere")

the def check(): is where I want the checker to be.
If any of you could point me in the right direction that would be great!