(square)
return square & 7
Gets the file index of square where `0` is the a file.
Gets the file index of square where `0` is the a file.
Gets the file index of square where 0 is the a file .
def file_index(square):
    """Gets the file index of square where `0` is the a file."""
    return square & 7
def file_index ( square ) : return square & 7