Python: read and write binary files

def copy(if_path, of_path):
    with open(if_path, 'rb') as in_file, open(of_path, 'wb') as out_file:
        while True:
            chunk = in_file.read(1024)
            if chunk:
                out_file.write(chunk)
                out_file.flush()
            else:
                break