AttributeError: 'str' object has no attribute 'items'

Question

In the following code:

#!/usr/local/bin/python import json  APPLICATION_NAME = 'cc9226315643df89-36bf02429075329d0ba36748360d050c'  HEADERS1 = json.dumps(dict(Destination = u"/api/af/latest/applications/%s/rulesets" % (APPLICATION_NAME))) print "Headers1 is %s" % (HEADERS1) HEADERS2 = {'Destination': '/api/af/latest/applications/%s/rulesets' % (APPLICATION_NAME)} print "Headers2 is %s" % (HEADERS2) 

I get the following output:

Headers1 is {"Destination": "/api/af/latest/applications/cc9226315643df89-36bf02429075329d0ba36748360d050c/rulesets"} Headers2 is {'Destination': '/api/af/latest/applications/cc9226315643df89-36bf02429075329d0ba36748360d050c/rulesets'} 

but when I try to use either HEADER1 or HEADER2 in a REST call using requests(), I get very different results:

SERVER_URL = 'http://1.1.33.109:8087%s' % (APP_PATH) REQ_DATA = None print "Headers are: ", HEADERS print "SERVER_URL is: ", SERVER_URL print "Request Data is:", REQ_DATA print ""  RESPONSE = requests.request(     'MOVE',      SERVER_URL,      auth = ('admin', 'admin'),      verify = False,      data = REQ_DATA,     headers = HEADERS1 )     #<-- If I use HEADER1 it breaks, if I use HEADER2 it works print "Move Ruleset back to the Application RESULT: %s\n" % (RESPONSE) 

I get the following with HEADER1:

Traceback (most recent call last):    File "./myrest.py", line 234, in <module>      headers = HEADERS1 )    File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/requests/api.py", line 44, in request      return session.request(method=method, url=url, **kwargs)    File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/requests/sessions.py", line 324, in request      prep = req.prepare()    File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/requests/models.py", line 223, in prepare      p.prepare_headers(self.headers)    File "/usr/local/Cellar/python/2.7.5/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/requests/models.py", line 340, in prepare_headers      headers = dict((name.encode('ascii'), value) for name, value in headers.items()) AttributeError: 'str' object has no attribute 'items' 

If I use HEADER2 it executes cleanly:

Move Ruleset back to the Application RESULT: Response [200]

Can anyone explain what the differences are?

Answer 1

You are passing in a string; headers can't ever be a JSON encoded string, it is always a Python dictionary.

The print results are deceptive; JSON encoded objects look a lot like Python dictionary representations but they are far from the same thing.

The requests API clearly states that headers must be a dictionary:

• headers – (optional) Dictionary of HTTP Headers to send with the Request.

JSON data is something you'd send as content to another server, not something you'd use to communicate with a Python API.

Answer 2

I had this issue and I needed to make the header with a content type and pass in a data element as json.

import requests import json  headerInfo = {'content-type': 'application/json' } payload = {'text': 'okay!!!', 'auth_token': 'aasdasdasdasd'} jLoad = json.dumps(payload)  r = requests.post('http://example.com:3030/widgets/init', headers=headerInfo, data=jLoad) print r.text print r.status_code