如何在Python中将一个字节的int更改为两个字节？

Question

I am making a basic server/client program, and I am making the client in Python. I have to format the message before I send it. The first field is for message length. I can compute the message length, but I need to store the value in the first two bytes of my bytearray. If the message length is less than 256, it should be only one byte. How can I force the number to be 2 bytes without just tacking a 0x00 onto the front?

Answer 1

Use the struct module . For example, to pack an integer into an unsigned two-byte value in network order (big-endian), you would do this:

> my_value = 1234
> packed_bytes = struct.pack('>H', my_value)
> print packed_bytes
'\x04\xd2'