Access to watermark offsets API in python

[aaronhays]

I just ran across confluentinc/librdkafka#503 after spending some time hacking in a solution using the available Python APIs that I'm too embarrassed to discuss publicly. It works fine for initial offset queries, but is not sufficient for keeping track of the current highwater mark during consumption. It would be great to get access to these APIs in Python. Is this on the roadmap anywhere?

I would prefer not to hack this in myself because I'm not quite sure how to correctly manage the memory for those int64_t * output parameters (low and high) between C and Python, as I'm not proficient with the Python C-API. I would probably adapt the interface to return a tuple of low and high and raise an exception in the case of error, but I don't know if that is the best way to proceed.

[edenhill]

Merged!