As was mentioned by cco:
if data.char in "123456789" data.board[row][col] = int(data.char)
The in operator evaluates to true if it finds a variable in the specified sequence and false otherwise. It can be used for lists, strings, tuples and dictionaries. However the in will only check the keys of the dictionary – not the values.
If you wanted ints for example, you could declare a list of numbers and use that instead.
if num in [1,2,3,4,5,6,7,8,9]: do something
if num in range(1,9): do something
solved Shortening the following if statement?