Various errors while parsing JSON in Python

Question

Attempting to parse json from a url requiring login. Including all my code here as I'm not sure where the error is.

try: import simplejson as json
except ImportError: import json
import urllib2

username = 'user'
password = '1234'
url = "https://www.blah.com/someplace"

# set up the username/password/url request
password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
password_mgr.add_password(None, "https://www.blah.com", username, password)
handler = urllib2.HTTPBasicAuthHandler(password_mgr)
opener = urllib2.build_opener(handler)
urllib2.install_opener(opener)
request = urllib2.Request(url)
response = opener.open(request)

# option 1
json_object = json.loads(str(response))

#option 2
json_object = json.loads(response)

If I run the code with option 1 (commenting out option 2), I get this error:

Traceback (most recent call last):
  File "jsontest.py", line 22, in <module>
    json_object = json.loads(str(request))
  File "/usr/lib/python2.7/dist-packages/simplejson/__init__.py", line 413, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/dist-packages/simplejson/decoder.py", line 402, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python2.7/dist-packages/simplejson/decoder.py", line 420, in raw_decode
    raise JSONDecodeError("No JSON object could be decoded", s, idx)
simplejson.decoder.JSONDecodeError: No JSON object could be decoded: line 1 column 0 (char 0)

If I run option 2:

Traceback (most recent call last):
  File "jsontest.py", line 23, in <module>
    json_object = json.loads(request)
  File "/usr/lib/python2.7/dist-packages/simplejson/__init__.py", line 413, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/dist-packages/simplejson/decoder.py", line 402, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
TypeError: expected string or buffer

My sample JSON is valid as far as I can tell:

{"set1":[{"data1":"411","data2":"2033","data3":"1","data4":"43968077","data5":"217","data6":"106828","data7":[]}], "set2":{"data8":"411","data9":"2033","data10":"43968077","data11":"217223360","data12":"106828"}}

simplejson version = 2.3.2, Python 2.7.3

Very new to all this so any pointers would be very helpful.

Godforsaken

why are you trying to read the request object? Don't you want the response? response = opener.open(req);data = response.read() – Fraternity

Don't you mean json_object = json.loads(response)? (not request?) Just a typo? – Philippine

Ugh. Yes I meant response. Edited. – Godforsaken

Answer 1

You want to decode the response, not the request:

json_object = json.load(response)

The response is a file-like object, so you can use .load() to have the json library read it directly.

Alternatively (at the cost of some temporary memory use), use the .loads() function with the fully read response:

json_object = json.loads(response.read())

Note that python 2.7 already includes the simplejson library, renamed to json:

import json

Tubby

Correct, I needed to use .read() or load(). The 'response' was a typo yes. I now have a ready-to-go py dict, thanks! – Godforsaken

Answer 2

You need to use response, not request (maybe just a typo?), but furthermore you need to use response.read() to get the body of the HTTP response:

json_object = json.loads(response.read())

Philippine