在标头中设置Content-Type / application / json

Question

I'm using urllib2 to create an HTTP request, I need to set Content-Type : application/json in the header, but it doesn't seem to be working

request = urllib2.Request(url, data='\"type\":\"chain\",\"data\":null')
request.add_header("Authorization", "Basic %s" % creds)
request.add_header("Content-Type", "application/json")
request.add_header("Accept", "application/json")
print "Data: %s" % request.get_data()
print "Accept: %s" % request.get_header("Accept")
print "Content-Type: %s" % request.get_header("Content-Type")
print "Authorization: %s" % request.get_header("Authorization")

The results are:

Data: "type":"chain","data":null

Accept: application/json

Content-Type: None

Authorization: Basic U1lTQ1RMOmFiYzEyMw==

As you can see, even though I'm setting "Content Type", its coming back "None".

Any help would be appreciated

Answer 1

That's because of an inconsistency in the urllib2.Request header accessor methods - namely, add_header() auto-capitalizes your header when storing, but get_header() doesn't do the same when retrieving, so if you do:

print "Content-Type: %s" % request.get_header("Content-type")

or

print "Content-Type: %s" % request.get_header("Content-Type".capitalize())

everything should show up fine. Headers, by all HTTP specifications, should be treated as case-insensitive anyway, sadly most HTTP libraries out there doesn't respect that fact.

Answer 2

我能够确定add_header（）方法不喜欢大写的“ Type”，将其更改为request.add_header（“ Content-type”，“ application / json”）解决了该问题。