Basically what you do is correct. Looking at redmine docs you linked to, it seems that suffix after the dot in the url denotes type of posted data (.json for JSON, .xml for XML), which agrees with the response you get - Processing by AttachmentsController#upload as XML. I guess maybe there's a bug in docs and to post binary data you should try using http://redmine/uploads url instead of http://redmine/uploads.xml.
Btw, I highly recommend very good and very popular Requests library for http in Python. It's much better than what's in the standard lib (urllib2). It supports authentication as well but I skipped it for brevity here.
import requests
with open('./x.png', 'rb') as f:
data = f.read()
res = requests.post(url='http://httpbin.org/post',
data=data,
headers={'Content-Type': 'application/octet-stream'})
# let's check if what we sent is what we intended to send...
import json
import base64
assert base64.b64decode(res.json()['data'][len('data:application/octet-stream;base64,'):]) == data
UPDATE
To find out why this works with Requests but not with urllib2 we have to examine the difference in what's being sent. To see this I'm sending traffic to http proxy (Fiddler) running on port 8888:
Using Requests
import requests
data = 'test data'
res = requests.post(url='http://localhost:8888',
data=data,
headers={'Content-Type': 'application/octet-stream'})
we see
POST http://localhost:8888/ HTTP/1.1
Host: localhost:8888
Content-Length: 9
Content-Type: application/octet-stream
Accept-Encoding: gzip, deflate, compress
Accept: */*
User-Agent: python-requests/1.0.4 CPython/2.7.3 Windows/Vista
test data
and using urllib2
import urllib2
data = 'test data'
req = urllib2.Request('http://localhost:8888', data)
req.add_header('Content-Length', '%d' % len(data))
req.add_header('Content-Type', 'application/octet-stream')
res = urllib2.urlopen(req)
we get
POST http://localhost:8888/ HTTP/1.1
Accept-Encoding: identity
Content-Length: 9
Host: localhost:8888
Content-Type: application/octet-stream
Connection: close
User-Agent: Python-urllib/2.7
test data
I don't see any differences which would warrant different behavior you observe. Having said that it's not uncommon for http servers to inspect User-Agent header and vary behavior based on its value. Try to change headers sent by Requests one by one making them the same as those being sent by urllib2 and see when it stops working.
Basically what you do is correct. Looking at redmine docs you linked to, it seems that suffix after the dot in the url denotes type of posted data (.json for JSON, .xml for XML), which agrees with the response you get - Processing by AttachmentsController#upload as XML. I guess maybe there's a bug in docs and to post binary data you should try using http://redmine/uploads url instead of http://redmine/uploads.xml.
Btw, I highly recommend very good and very popular Requests library for http in Python. It's much better than what's in the standard lib (urllib2). It supports authentication as well but I skipped it for brevity here.
import requests
with open('./x.png', 'rb') as f:
data = f.read()
res = requests.post(url='http://httpbin.org/post',
data=data,
headers={'Content-Type': 'application/octet-stream'})
# let's check if what we sent is what we intended to send...
import json
import base64
assert base64.b64decode(res.json()['data'][len('data:application/octet-stream;base64,'):]) == data
UPDATE
To find out why this works with Requests but not with urllib2 we have to examine the difference in what's being sent. To see this I'm sending traffic to http proxy (Fiddler) running on port 8888:
Using Requests
import requests
data = 'test data'
res = requests.post(url='http://localhost:8888',
data=data,
headers={'Content-Type': 'application/octet-stream'})
we see
POST http://localhost:8888/ HTTP/1.1
Host: localhost:8888
Content-Length: 9
Content-Type: application/octet-stream
Accept-Encoding: gzip, deflate, compress
Accept: */*
User-Agent: python-requests/1.0.4 CPython/2.7.3 Windows/Vista
test data
and using urllib2
import urllib2
data = 'test data'
req = urllib2.Request('http://localhost:8888', data)
req.add_header('Content-Length', '%d' % len(data))
req.add_header('Content-Type', 'application/octet-stream')
res = urllib2.urlopen(req)
we get
POST http://localhost:8888/ HTTP/1.1
Accept-Encoding: identity
Content-Length: 9
Host: localhost:8888
Content-Type: application/octet-stream
Connection: close
User-Agent: Python-urllib/2.7
test data
I don't see any differences which would warrant different behavior you observe. Having said that it's not uncommon for http servers to inspect User-Agent header and vary behavior based on its value. Try to change headers sent by Requests one by one making them the same as those being sent by urllib2 and see when it stops working.
This has nothing to do with a malformed upload. The HTTP error clearly specifies 401 unauthorized, and tells you the CSRF token is invalid. Try sending a valid CSRF token with the upload.
More about csrf tokens here:
What is a CSRF token ? What is its importance and how does it work?
from what you say, you're running python3 (as the StringIO package has been renamed io in python3, not python2) and your example is python2 (for obvious reasons).
So for your issue:
"TypeError:initial_value must be str or None, not bytes".
What that means is that in:
response = requests.get('http://www.github.com')
you're either getting None or a response in bytes for response.content. Given that your request worked, and you can access response.content, it is very likely to be in bytes.
As the requests library works at a quite low level, and all data coming in and to sockets (including the HTTP socket) is plain binary (i.e. not interpreted), to be able to use the output in string functions you need to convert it into something.
In python3 str is the old unicode from python2, and bytes is close to the old str of python2. So you would need to convert the bytes into a string to feed StringIO:
i = Image.open(StringIO(response.content.decode('utf-8')))
for example. But then I'm expecting Image.open() to yell at you that it does not know wtf it is supposed to do with a unicode buffer, all it really wants is a byte array!
But because Image.open() is actually expecting a stream of bytes, and not a unicode stream, what you shall be doing is actually use a BytesIO instead of a StringIO:
from io import BytesIO
i = Image.open(BytesIO(response.content))
Finally, you're sweet to give an example, but it's not one that would work, as you're giving a link to an HTML page, instead of an image.
HTH
It's a good idea to actually fetch an image from the internet if one wants to parse images :D (as opposed to fetching the index page at github.com)
import requests
from PIL import Image
from StringIO import StringIO
url = "https://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Venn0110.svg/576px-Venn0110.svg.png"
response = requests.get(url)
i = Image.open(StringIO(response.content))
The example you're trying to use looks different from what you've posted here:
3.3.4 Binary Response Content
You can also access the response body as bytes, for non-text requests:
>>> r.content
b'[{"repository":{"open_issues":0,"url":"https://github.com/...
The gzip and deflate transfer-encodings are automatically decoded for you.
For example, to create an image from binary data returned by a request, you can use the following code:
>>> from PIL import Image
>>> from StringIO import StringIO
>>> i = Image.open(StringIO(r.content))
https://github.com/... <-- these three dots (ellipses) indicate that the URL has been shortened in the example.
source: Requests Documentation Release 2.9.1