Tic-Tac-Toe game in Python-3.x
A few quick comments, in no particular order:



Python 3 uses print as a function, not a statement



You’ve tagged the question with [python-3.x], but the code uses print statements, not functions. If I try to run the code with Python 3, I immediately get an error:

  File "tictactoe.py", line 2
    print "The board look like this: \n"
                                       ^
SyntaxError: Missing parentheses in call to 'print'




Henceforth I’ll assume that you’re actually using Python 2.x, and the question was just mistagged.



Don’t catch overly broad exceptions.



In your get_input() function, you have except Exception as e, to catch the case where the user enters something that isn’t an integer. You can improve this in two ways:


Only catch the exception you‘re expecting to throw. If you catch plain Exception, you risk losing information about unexpected errors.

In this case, you might get a ValueError if the user gives a string which can’t be coerced to an integer, so catch ValueError’s instead.
Limit the amount of code in the try block. The only line you expect to throw an exception is user = int(user), but you’ll catch exceptions thrown in any of the surrounding lines. Better to only include that line in the try block – again, you won’t lose information about unexpected errors.




Here’s how you can rewrite the body of the get_input() function accordingly:

user = raw_input("Where would you like to place " + turn + " (1-9)?
try:
    user = int(user)
except ValueError:
    print user + " is not a valid move! Please try again.\n"
    continue
if 1 &lt;= user &lt;= 9:
    return user-1
else:
    print "That is not a valid move! Please try again.\n"
    print_instruction()




That said, I was unable to find any invalid input that caused the script to crash – kudos.

Looking further, I see something worse in check_win():

try:
    if board[each[0]-1] == board[each[1]-1] and board[each[1]-1] == board[each[2]-1]:
        return board[each[0]-1]
except:
    pass




You should never do except: pass. This will (silently) swallow every form of exception – including SystemExit and KeyboardInterrupt, which you almost certainly don’t want to catch. In this case, you probably want to catch KeyError instead.



Get rid of the valid variable in get_input()



Its value is never actually used – it just serves to keep the loop going perpetually until the function returns. Better to use while True than track an unused variable.

Likewise for win in the main function.



Add comments and docstrings



There’s very little in the way of commentary in this code. That makes it hard to follow, and it will make things difficult when you come to maintain it in future.

Comments will help understand why you’ve written the code this way – for example, in get_input(), why do we decrement 1 from the value provided by the user? And docstrings are important if you want your code to be reusable.