Implement flexbuffers in python

[dmitriykovalev]

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[aardappel]

@rw

[rw]

@dmitriykovalev Can you bump this thread to get CI to run again? We had a travis outage.

[dmitriykovalev]

@rw I've rebased, all checks passed.

[rw]

@dmitriykovalev This looks great! Can you show me where the tests are running in Travis, if they are? I looked through the big test-everything-with-Docker test log, and what I saw was this: the number of unittests run with Python2 and with Python3 were the same. I found that I could grep for the tokens python_2 and python_3 to determine this. Could you help me make sure this is getting tested like we think?

I'll also note that (perhaps after we merge this PR) it would be good to add fuzz tests to this feature.

[dmitriykovalev]

@rw Thanks! Tests should be picked up by running tests/PythonTest.sh. I'm not familiar with Travis integration for this project but looks like that's the only way to run python tests. You should see something like Ran 60 tests in 0.282s — these 60 tests are flexbuffers tests. There are 114 old tests, so you'll see Ran 114 tests in 0.054s as well.

Regarding fuzz tests, sure, that's something to add on top. For python that shouldn't be super critical because bad input would end up in some kind of exception anyway, not a program crash like in C/C++.

[aardappel]

Ok, merging this for now, since a) it's seen code review and testing elsewhere, and b) this is a new API not in use by anyone yet. Followups can provide further improvements.. thanks all!