Tic-Tac-Toe game for Recurse Center by Josh Stein

tic-tac-toe.py

#tic-tac-toe game for Recurse Center by Josh Stein

"""
1) print tic-tac-toe blank board
2) set turns to zero
3) receive user input = [1,9]
4) if else = try again
5) check if user_input is already taken
6) add user input to the board
7) check if user won (rows, columns, diagonals)
8) toggle between users
9) declare winner or tie
"""

board = [
  ["-", "-", "-"],
  ["-", "-", "-"],
  ["-", "-", "-"]
]

user = True #when true X, otherwise O
turns = 0

def print_board(board):
  for row in board:
    for slot in row:
      print(f"{slot} ", end="")
    print()

def quit(user_input):
  if user_input.lower() == "q": 
    print("Thanks for playing!")
    return True
  else: return False


def check_input(user_input):
  # check if input is number
  if not isnum(user_input): return False
  user_input = int(user_input)
  # check if [1,9]
  if not bounds(user_input): return False
  return True

def isnum(user_input):
  if not user_input.isnumeric(): 
    print("This is not a valid number")
    return False
  else: return True

def bounds(user_input):
  if user_input > 9 or user_input < 1: 
    print("This is number is off the board")
    return False
  else: return True

def istaken(coords, board):
  row = coords[0]
  col = coords[1]
  if board[row][col] != "-":
    print("This position is taken.")
    return True
  else: return False

def coordinates(user_input):
  row = int(user_input / 3)
  col = user_input
  if col > 2: col = int(col % 3)
  return (row,col)

def add_to_board(coords, board, active_user):
  row = coords[0]
  col = coords[1]
  board[row][col] = active_user

def current_user(user):
  if user: return "x"
  else: return "o"

def iswin(user, board):
  if check_row(user, board): return True
  if check_col(user, board): return True
  if check_diag(user, board): return True
  return False

def check_row(user, board):
  for row in board:
    complete_row = True
    for slot in row:
      if slot != user:
        complete_row = False
        break
    if complete_row: return True
  return False 

def check_col(user, board):
  for col in range(3):
    complete_col = True
    for row in range(3):
      if board[row][col] != user:
        complete_col = False
        break
    if complete_col: return True
  return False

def check_diag(user, board):
  #top left to bottom right
  if board[0][0] == user and board[1][1] == user and board[2][2] == user: return True
  elif board[0][2] == user and board[1][1] == user and board[2][0] == user: return True
  else: return False

while turns < 9:
  active_user = current_user(user)
  print_board(board)
  user_input = input("Please enter a position 1-9 or enter \"q\" to quit:")
  if quit(user_input): break
  if not check_input(user_input):
    print("Please try again.")
    continue
  user_input = int(user_input) - 1
  coords = coordinates(user_input)
  if istaken(coords, board):
    print("Please try again.")
    continue
  add_to_board(coords, board, active_user)
  if iswin(active_user, board): 
    print(f"{active_user.upper()} won!")
    break
  
  turns += 1
  if turns == 9: print("Tie!")
  user = not user