Method write

Lib/test/test_importlib/test_util.py:793–797

(fd, data)

        # Emulate an os.write that only writes partial data.
        def write(fd, data):
            if self.seen_write and self.never_complete:
                return None
            self.seen_write = True
            return oldwrite(fd, data[:self.truncate_at_length])

        # Need to patch _io to be _pyio, so that io.FileIO is affected by the
        # os.write patch.