Decoding JSON with Python

Question

Why do I get

ValueError: No JSON object could be decoded

from this code:

import urllib.request,json 
n = urllib.request.urlopen("http://graph.facebook.com/55")
d = json.loads(str(n.readall()))

The full error:

Traceback (most recent call last):
 File "<pyshell#41>", line 1, in <module>
 d= json.loads(str(n.readall()))
 File "C:\Python33\lib\json\__init__.py", line 309, in loads
 return _default_decoder.decode(s)
 File "C:\Python33\lib\json\decoder.py", line 352, in decode
 obj, end = self.raw_decode(s, idx=_w(s, 0).end())
 File "C:\Python33\lib\json\decoder.py", line 370, in raw_decode
 raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded

The output of str(n.readall()):

'b\'{"id":"55","name":"Jillian Copeland","first_name":"Jillian","last_name":"Copeland","username":"JCoMD","gender":"female","locale":"en_US"}\''

Maybe the b is throwing it off?

If that is the issue, how do I convert the binary stream from the readall to a string and not have that b?

I am trying to learn a little python so please keep that in mind.

I am using Python 3.3 in Windows.

• Martijn Pieters: possible duplicate of Use "byte-like object" from urlopen.read with json?

Answer 1

I believe that this is an exact duplicate of this question, but sadly there's no accepted answer.

On my end, this works:

import urllib.request,json 
n = urllib.request.urlopen("http://graph.facebook.com/55")
d= json.loads(n.readall().decode('utf-8'))

• Bill Lynch: If I don't decode, I get this: TypeError: can't use a string pattern on a bytes-like object. I am using python 3.1 instead of 3.3, so that may be why though.
• Bill Lynch: What I am missing here though, is how we determine that the response is UTF-8, and not in some other encoding. I didn't look into how to pull that from the urllib request.
• Martijn Pieters: The content-type header tells you that.