Receiving gzip with Flask

Question

I'm trying to receive a gzipped JSON file from an HTTP POST to Flask (v0.10). I feel there may be some extra data posted that needs stripping out before trying to open the gzip.

Here's the code I have:

from flask import Flask, jsonify, request, abort
import gzip, StringIO
app = Flask(__name__)

# Handle posted data
@app.route('/', methods = ['POST'])
def post_gzip():

    # Check for a supported media type
    if (request.headers['Content-Type'] == 'application/x-gzip'):

        file = request.data
        f = gzip.open(file, 'rb')        

        return f;

    else:
        # 415 Unsupported Media Type
        abort(415)

if __name__ == "__main__":
    app.debug = True
    app.run()

I'm posting a zipped JSON file to Flask with cURL as follows:

curl -X POST -d @test.json.gz http://127.0.0.1:5000/ -H "Content-Type:application/x-gzip" -H "Content-Encoding:gzip"

And the error I'm receiving is:

UnicodeDecodeError: 'utf8' codec can't decode byte 0x8b in position 1: invalid start byte

It seems like Flask can't see the received data as being a gz file. Perhaps request.data isn't the right thing to use even.

Could some kind person point me in the right direction with this one?

Answer 1

For Python 3, I would just use gzip.decompress(request.data) which returns a decompressed string.

It's just a convenient shorthand function, added 8 years ago :)

If you want to take a look at the code, you can find it here.

2019 edit: wrote a simple flask extension you can use in your app.