Support for floats?

[idubz33]

I've just come across this library and after checking out the documentation at https://digidotcom.github.io/python-suitcase/latest/api.html I was wondering why there isn't support for floats?

[rtzoeller]

Likely because no one had needed them in a use case up until now -- AFAIK, the addition of new field types has largely been on an as-needed basis.

Is there a particular protocol you have in mind that requires floats to be encoded as bytes, as opposed to a text-based implementation?

[idubz33]

Fair enough, I'm not working with a particular protocol but rather with parsing and repacking some uncommon 3D graphic model files (as you can imagine a lot of vector fields containing floats). Originally I used the struct library which had float support but suitcase is vastly more eloquent... I can't go back :P

I'm not sure what you mean by a text-based implementation, can you please elaborate? If its possible to cover 16/32/64 bit floats I'd be really grateful.

[posborne]

I would accept a PR adding floating point support. You should be able to add basic support easily by using the struct format strings similar to the existing ones like https://github.com/digidotcom/python-suitcase/blob/master/suitcase/fields.py#L1055

[idubz33]

Sorry to reopen this again but @posborne its seems that the way this package unpacks data can't be done for floats. I'm getting the following error:

  File "/Library/Python/2.7/site-packages/suitcase/fields.py", line 1005, in unpack
    value |= (byte << (i * 8))
suitcase.exceptions.SuitcaseParseError: Unexpected exception while unpacking field 'Rotation_X': unsupported operand type(s) for <<: 'float' and 'int'

The unpack definition would require change to allow floats https://github.com/digidotcom/python-suitcase/blob/master/suitcase/fields.py#L998. Any suggestions?