tik_tac_toe practice assignment in python

Question

Im just starting out with my python learning, and having reached my first capstone project (tik_tak_toe) using jupyter notebook, I wondered if there was a cleaner and/more efficient way of running my check to determine a winner. Just to fully clarify for context:

-"board" in a numeric pattern similar to that on a full sized keyboard (top = 7,8,9 middle = 4,5,6 etc)

• the board is created in a dictionary, with keys 1-9

• key values are altered by (user = int(input('number')), then board[user] = 'X' / 'Y'

   def result_check(test):
       # VERTICAL WIN_CHECK
   if ('X' in test[1] and test[2] and test[3]) :
       return True
   elif ('Y' in test[1] and test[2] and test[3]):
       return
   elif ('X' in test[4] and test[5] and test[6]):
       return True
   elif ('Y' in test[4] and test[5] and test[6]):
       return True
   elif ('X' in test[7] and test[8] and test[9]) :
       return True
   elif ('Y' in test[7] and test[8] and test[9]):
       return True
       # HORIZONTAL WIN _CHECK
   elif ('X' in test[7] and test[4] and test[1]):
       return True
   elif ('Y' in test[7] and test[4] and test[1]):
       return True
   elif ('X' in test[8] and test[5] and test[2]):
       return True
   elif ('Y' in test[8] and test[5] and test[2]):
       return True
   elif ('X' in test[9] and test[6] and test[3]):
       return True
   elif ('Y' in test[9] and test[6] and test[3]):
       return True
             # DIAGONAL WIN_CHECK
   elif ('X' in test[7] and test[5] and test[3]):
       return True
   elif ('Y' in test[7] and test[5] and test[3]):
       return True
   elif ('X' in test[9] and test[5] and test[1]):
       return True
   elif ('Y' in test[9] and test[5] and test[1]):
       return true
   else:
       return False
  

Answer 1

Since you said you are new to python, are you new to programming in general? If not, is there a reason you have the board as a single list rather than a nested list? And are you aware of loops? Because depending on your knowledge level we can know how into how much detail we should go in explaining.

To illustrate a normal list would be test=["X","X","X","O","O","O","O","O","O"] while a nested list would be test=[["X","X","X"],["O","O","O"],["O","O","O"]]. You would do so because it would make looping over it much easier.

Generally in programming if you have a lot of if-else statements chances are you can automate them using loops. Here's an example of the horizontal check:

def check(inputList):
    for i in range(0,9,3):
        winner=0
        for j in range(3):
            if test[i+j]=="X":
                winner+=1
        if winner==3:
            return True
    return False

How does it work?

• First we start with a loop that goes from 0 to 9 in steps of 3, so it assumes the following values: (0,3,6). This is basically for each "line"
• then we use a helping variable to count the amount of "X"es in the line
• next we use another loop WITHIN that loop that loops from 0 to 3 in steps of 1 so it has the values (0,1,2)
• now we check every entry in the line and if it's a "X" we add 1 to winner.
• then after we checked the line if the value of "winner" is 3, we return true.

If you wanted to do the same for a win of "Y" as well, just check for a "Y" and use winner-=1. If winner==-3 after the line you know that "Y" won.

You can do the same for the lines by switching around the loops a bit. For the diagonal test, you can just use if conditions, it's just two checks after all.