Flexbuffer or bytearray support for python [python 3.x, flatc 1.7.1, Ubuntu 16.04 LTS, flatbuffers 2015.5.14]

[jfinken]

• python 3.X
• flatc version 1.7.1 (Sep 27 2017)
• Ubuntu 16.04.2 LTS
• flatbuffers serialization format for Python: INSTALLED: 2015.5.14.0

I would like to store a python bytearray in a flatbuffer vector of type byte without having to iterate over the incoming bytearray invoking builder.PrependByte, e.g.:

for j in reversed(range(0, len(buf))):
        builder.PrependByte(buf[j])  

Is this possible via Flexbuffers or other given the current implementation(s)? Otherwise, for serialization performance reasons the above prevents usage within my use case.

Many thanks in advance.

[aardappel]

We should really just add a special purpose function for byte arrays.
I believe this was discussed elsewhere too, not sure why it didn't happen.. @rw?

[rw]

We have functions for reading byte arrays (from #4390) but not yet for writing them.

I've created a PR that implements your request: #4453

Please try it out and provide feedback.

(Also, you'll want to default to installing the python package from git (using pip3 install -e git+ssh://...) to get more up-to-date code.)

[aardappel]

Fixed here: #4453

[adsharma]

https://github.com/adsharma/flexpy has some python3 compatible code to read flexbuffers.
Warning: hot off the press, needs more review.
Could use numpy to avoid copies.