Python 3 issue: client.publish does not accept bytes payload as returned by struct.pack

[jpwsutton]

migrated from Bugzilla #486185
status UNCONFIRMED severity normal in component MQTT-Python for 1.2
Reported in version 1.1 on platform All
Assigned to: Roger Light

On 2016-01-20 11:12:07 -0500, Andreas Koehler wrote:

The documentation suggests using struct.pack() to create payloads.

But invoking e.g. client.publish("test",struct.pack('>d',1.2345)) results in an error:

File "D:\Miniconda3\envs\python34\lib\site-packages\paho\mqtt\client.py", line 871, in publish
raise TypeError('payload must be a string, bytearray, int, float or None.')

This is because client.publish only checks isinstance(payload, bytearray), but not isinstance(payload, bytes), which is what struct.pack returns on Python 3

Easy fix in client.py on line 864: for sys.version_info[0]==3 use isinstance(payload, bytes) instead of isinstance(payload, unicode)

Workaround: use bytearray(struct.pack(...)) to create payload.

On 2016-01-20 11:18:54 -0500, Andreas Koehler wrote:

Regarding the fix - it's not only line 864... there are more type checks on the payload later on...