Hi,

@mindintelligence wrote
I have created a sentence to assign which player take which letter whether x or o 
and I have created many statements but they didn’t work

Your function main() assigns a letter to the player but its invocation is put at the end of the script (and it is conditional for some reason). You should move the invocation to the place before the part of the code that carries on the game. I modified your code a bit putting some comments into it. Look at the snippet below.

import random

board = [" ", " ", " ", " ", " ", " ", " ", " ", " ", " "]
game_letters = ['X', 'O']

# Y: players' names are strings rather than integers, so initial values of corresponding variables should be empty strings 
player1 = ''
player2 = ''

# Y: I have no idea what this is for, however, interpreter accepts it :-)
# Y: possibly, it is a result of lost of formatting after pasting the code into DO editor
1 | 2 | 3
4 | 5 | 6
7 | 8 | 9

def draw_board(board):
    print('———')
    print(board[1] , '|' , board[2] , '|' , board[3])
    print('———')
    print(board[4] , '|' , board[5] , '|' , board[6])
    print('———')
    print(board[7] , '|' , board[8] , '|' , board[9])
    print('———')

# Y: I created this function to simply find opposite letter to the letter held by variable turn
# Y: for learning purposes you could modify this function to find the opposite letter within the letters available under the variable game_letters 
def opposite_turn(turn):
    if turn == 'X':
        return 'O'
    else:
        return 'X'

def main():
    draw_board(board)
    print("Welcome to TIC TAC TOE Game")
    player1 = print("Player 1 please enter your name: ")
    player1 = input().upper()
    player2 = print("Player 2 please enter your name: ")
    player2 = input().upper()    
    turn = input("Player " + str(player1) + " would you like to choose X or O?") .upper()
    # Y: it checks whether the letter entered  by user is acceptable, and if not, then asks for it again 
    while turn not in game_letters:
        turn = input("Player " + player1 + ", please choose just one letter: X or O  : ") .upper()
    # Y: I swapped the occurrences of variable thisplayer for variable turn and invocation of function opposite_turn() to print the chosen letters   
    print(player1 + " takes : " + turn + ',  ' + player2 + " takes : " + opposite_turn(turn))

# Y: I would invoke main() here to give the players a choice of letters before they start a game
main()
while True:
    draw_board(board)
    move = int(input(" Make a move (X): "))
    valid_move = [ ]
    for position in range(9):
        if board[position]==0:
            valid_move.append(position)
        if move in valid_move:
            break                    
    print("illegal move")
    board[move] = str("X")
    """if board[move] == str("X") or board[move] == str("O"):
        print("Please make another move ")"""
    draw_board(board)
    move_2 = int(input(" Make a move (O): "))
    valid_move= [ ]
    for position in range(9):
        if board[position]==0:
            valid_move.append(position)
        if move in valid_move:
            break                    
    print("illegal move")
    board[move_2] = str("O")
    """if board[move_2] == str("X") or board[move] == str("O"):
            print("Please make another move ")"""

    # player_1 choices
    if board[1] == board[2] == board[3] == "X":  #across the top row
        print(str(player_1)  +  "wins" )
        break
    elif board[4] == board[5] == board[6] == "X":  #across the middle row
        print(str(player_1)  +  "wins" )
        break
    elif board[7] == board[8] == board[9] == "X":  #across the bottom row
        print(str(player_1)  +  "wins" )
        break
    elif board[1] == board[4] == board[7] == "X":  #first column
        print(str(player_1)  +  "wins" )
        break
    elif board[2] == board[5] == board[8] == "X":  #second column
        print(str(player_1)  +  "wins" )
        break
    elif board[3] == board[6] == board[9] == "X":  #third column
        print(str(player_1)  +  "wins" )
        break
    elif board[1] == board[5] == board[9] == "X":  #left diagonal
        print(str(player_1)  +  "wins" )
        break
    elif board[3] == board[5] == board[7] == "X":  #right diagonal
        print(str(player_1)  +  "wins" )
        break

    # player_2 choices
    if board[1] == board[2] == board[3] == "O":  #across the top row
        print(str(player_2)  +  "wins" )
        break
    elif board[4] == board[5] == board[6] == "O":  #across the middle row
        print(str(player_2)  +  "wins" )
        break
    elif board[7] == board[8] == board[9] == "O":  #across the bottom row
        print(str(player_2)  +  "wins" )
        break
    elif board[1] == board[4] == board[7] == "O":  #first column
        print(str(player_2)  +  "wins" )
        break
    elif board[2] == board[5] == board[8] == "O":  #second column
        print(str(player_2)  +  "wins" )
        break
    elif board[3] == board[6] == board[9] == "O":  #third column
        print(str(player_2)  +  "wins" )
        break
    elif board[1] == board[5] == board[9] == "O":  #left diagonal
        print(str(player_2)  +  "wins" )
        break
    elif board[3] == board[5] == board[7] == "O":  #right diagonal
        print(str(player_2)  +  "wins" )
        break
    else:
        print(" It's a Tie ")

print("Game Over")

# Y: ?
def nextplayer(thisplayer):
    return (this_player+1)%2

# Y: ?
if name == 'main':
    main()

This code sometimes runs to some point and gives another error. Try to fix it by yourself as it is the best way to learn something, IMO. If you stuck, then post another question.

Keep coding :-)

P.S. I noticed that you convert into strings some values that are already the strings, e.g.

# the variable player1 gets string as a result of function input()
player1 = input().upper()
# so it is not needed to convert it into string again with str() function
print(str(player1))
# you can use 
print(player1)
# the code is clearer then and runs slightly faster (it is lesser to do for an interpreter)

input() function returns the string (even if a user entered a number), so you do not have to convert it into string again. More info here.

I hope it helps :-)