Help with simplifying the tie function

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Hi so for my AI class intro we had to programme a game. I made tic tac toe in python. If you look at the check_for_tie function, it looks a little bit too long and janky. Is there a way to simplify it?

#creating tic tac toe


# 1 create a board
# 2 print the board
# 3 create a function that asks the users for input.
# 4 create a function that checks for a win.

# global variable
game = True

#create a board

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

player_won = "none"

# create a function that prints the board
def print_board():
    print("|" + board[0] + "|" + board[1] + "|" + board[2] +  "|")
    print("|" + board[3] + "|" + board[4] + "|" + board[5] + "|")
    print("|" + board[6] + "|" + board[7] + "|" + board[8] + "|")


# create the functions that ask the two users for input. You wil have an x and an o


# we want it to ask for the position
def player_x():
    position = input("Choose your position from 1-9: ")
    position = int(position) - 1
    board[position] = "x"


# the function for player o
def player_o():
    position = input("Choose your position from 1-9: ")
    position = int(position) - 1
    board[position] = "o"

tie = False
# check for rows
def check_rows():
    global game
    row1 = board[0] == board[1] == board[2] != "-"
    row2 = board[3] == board[4] == board[5] != "-"
    row3 = board[6] == board[7] == board[8] != "-"
    if row1 or row2 or row3:
        game = False
    if row1:
        print("You have won, player: " + board[0])
    elif row2:
        print("You have won, player: " + board[3])
    elif row3:
        print("You have won, player: " + board[6])

# check for diagonals
def check_diagonals():
    global game
    diag1 = board[2] == board[4] == board[6] != "-"
    diag2 = board[0] == board[4] == board[8] != "-"
    if diag1 or diag2:
        game = False
    if diag1:
        return print("You have won, player: " + board[2])
    elif diag2:
        return print("You have won, player: " + board[0])

# check for columns
def check_columns():
    global game
    c1 = board[0] == board[3] == board[6] != "-"
    c2 = board[1] == board[4] == board[7] != "-"
    c3 = board[2] == board[5] == board[8] != "-"
    if c1 or c2 or c3:
        game = False
    if c1:
        return print("You have won, player: " + board[0])
    if c2:
        return print("You have won, player: " + board[1])
    if c3:
        return print("You have won, player: " + board[2])

# create a function where all the positions are filled in with x's or o's. So basically where everything doesn't equal "-".
def check_for_tie():
    global game
    b1 = board[0] and board[1] and board[2] and board[3] and board[4] and board[5] and board[6] and board[7] and board[8] != "-"
    if b1:
        game = False
        print("You have tied!")



# creating the check function
def check_for_winner():
    check_rows()
    check_diagonals()
    check_columns()

# creating the game loop


# this is the game loop that makes the code run
while game:
    print_board()
    player_x()
    check_for_winner()
    print_board()
    player_o()
    check_for_winner()
    check_for_tie()