Let JSON object accept bytes or let urlopen output strings


With Python 3 I am requesting a json document from a URL.

response = urllib.request.urlopen(request)

The response object is a file-like object with read and readline methods. Normally a JSON object can be created with a file opened in text mode.

obj = json.load(fp)

What I would like to do is:

obj = json.load(response)

This however does not work as urlopen returns a file object in binary mode.

A work around is of course:

str_response = response.read().decode('utf-8')
obj = json.loads(str_response)

but this feels bad...

Is there a better way that I can transform a bytes file object to a string file object? Or am I missing any parameters for either urlopen or json.load to give an encoding?

12/3/2018 6:33:01 PM

Accepted Answer

HTTP sends bytes. If the resource in question is text, the character encoding is normally specified, either by the Content-Type HTTP header or by another mechanism (an RFC, HTML meta http-equiv,...).

urllib should know how to encode the bytes to a string, but it's too naïve—it's a horribly underpowered and un-Pythonic library.

Dive Into Python 3 provides an overview about the situation.

Your "work-around" is fine—although it feels wrong, it's the correct way to do it.

5/3/2016 6:50:50 PM

Python’s wonderful standard library to the rescue…

import codecs

reader = codecs.getreader("utf-8")
obj = json.load(reader(response))

Works with both py2 and py3.

Docs: Python 2, Python3

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