streaming-form-data 1.0.0

Streaming parser for multipart/form-data

streaming_form_data provides a Python parser for parsing multipart/form-data input chunks (the most commonly used encoding when submitting data through HTML forms).

Chunk size is determined by the API user, but currently there are no restrictions on what the chunk size should be, since the parser works byte-by-byte (which means that passing the entire input as a single chunk should also work).

The main entry point is the StreamingFormDataParser class, which expects a dictionary of request headers.

The parser is fed chunks of (bytes) input, and takes action depending on what the current byte is. In case it notices input that’s expected (input that has been registered by calling parser.register, it will pass on the input to the registered Target class which will then decide what to do with it. In case there’s a part which is not needed, it can be associated to a NullTarget object and it will be discarded.

Currently the following Target classes are included with this library.

• ValueTarget - holds the input in memory

• FileTarget - pipes the input to a file on disk

• SHA256Target - computes the SHA-256 hash of the input

• NullTarget - discards the input completely

Any new targets should inherit streaming_form_data.targets.BaseTarget and define an on_data_received function.

Please note, that this library has only been tested with Python 3 (specifically, versions 3.3, 3.4, 3.5, and 3.6).

Installation

$ pip install streaming-form-data

In case you prefer cloning the Github repository and installing manually, please note that master is the development branch, so stable is what you should be cloning.

Usage

>>> from streaming_form_data import StreamingFormDataParser
>>> from streaming_form_data.targets import ValueTarget, FileTarget
>>>
>>> headers = {'Content-Type': 'multipart/form-data; boundary=boundary'}
>>>
>>> parser = StreamingFormDataParser(headers=headers)
>>>
>>> parser.register('name', ValueTarget())
>>> parser.register('file', FileTarget('/tmp/file.txt'))
>>>
>>> parser.data_received(chunk)

Development

To work on this package, please make sure you have a working Python 3 installation on your system.

1. Create a virtualenv - python -m venv venv && source venv/bin/activate.

2. Git clone the repository - git clone https://github.com/siddhantgoel/streaming-form-data

3. Install the packages required for development - pip install -r requirements.dev.txt

4. Install this package - pip install ..

5. You should now be able to run the test suite - py.test tests/.

Authors

• Siddhant Goel <@siddhantgoel>

• Sergey Kolomenkin <@kolomenkin>