Response Headers

We can view the server’s response headers using a Python dictionary:

>>> r.headers
{
    'content-encoding': 'gzip',
    'transfer-encoding': 'chunked',
    'connection': 'close',
    'server': 'nginx/1.0.4',
    'x-runtime': '148ms',
    'etag': '"e1ca502697e5c9317743dc078f67693f"',
    'content-type': 'application/json'
}

The dictionary is special, though: it’s made just for HTTP headers. According to RFC 7230, HTTP Header names are case-insensitive.

So, we can access the headers using any capitalization we want:

>>> r.headers['Content-Type']
'application/json'
>>> r.headers.get('content-type')
'application/json'

It is also special in that the server could have sent the same header multiple times with different values, but requests combines them so they can be represented in the dictionary within a single mapping, as per RFC 7230:

A recipient MAY combine multiple header fields with the same field name into one “field-name: field-value” pair, without changing the semantics of the message, by appending each subsequent field value to the combined field value in order, separated by a comma.