python - Making a POST call instead of GET using urllib2

Question

There's a lot of stuff out there on urllib2 and POST calls, but I'm stuck on a problem.

I'm trying to do a simple POST call to a service:

url = 'http://myserver/post_service'
data = urllib.urlencode({'name' : 'joe',
                         'age'  : '10'})
content = urllib2.urlopen(url=url, data=data).read()
print content

I can see the server logs and it says that I'm doing GET calls, when I'm sending the data argument to urlopen.

The library is raising an 404 error (not found), which is correct for a GET call, POST calls are processed well (I'm also trying with a POST within a HTML form).

Answer 1

Do it in stages, and modify the object, like this:

# make a string with the request type in it:
method = "POST"
# create a handler. you can specify different handlers here (file uploads etc)
# but we go for the default
handler = urllib2.HTTPHandler()
# create an openerdirector instance
opener = urllib2.build_opener(handler)
# build a request
data = urllib.urlencode(dictionary_of_POST_fields_or_None)
request = urllib2.Request(url, data=data)
# add any other information you want
request.add_header("Content-Type",'application/json')
# overload the get method function with a small anonymous function...
request.get_method = lambda: method
# try it; don't forget to catch the result
try:
    connection = opener.open(request)
except urllib2.HTTPError,e:
    connection = e

# check. Substitute with appropriate HTTP code.
if connection.code == 200:
    data = connection.read()
else:
    # handle the error case. connection.read() will still contain data
    # if any was returned, but it probably won't be of any use

This way allows you to extend to making PUT, DELETE, HEAD and OPTIONS requests too, simply by substituting the value of method or even wrapping it up in a function. Depending on what you're trying to do, you may also need a different HTTP handler, e.g. for multi file upload.