Request and response objects
When a page is requested, Django creates an HttpRequest object that contains metadata about the request. Then Django loads the appropriate view, passing the as the first argument to the view function. Each view is responsible for returning an HttpResponse object.
This document explains the APIs for and HttpResponse objects, which are defined in the module.
HttpRequest
objects
class HttpRequest
All attributes should be considered read-only, unless stated otherwise.
HttpRequest.scheme
A string representing the scheme of the request (http
or https
usually).
HttpRequest.body
The raw HTTP request body as a bytestring. This is useful for processing data in different ways than conventional HTML forms: binary images, XML payload etc. For processing conventional form data, use .
You can also read from an HttpRequest
using a file-like interface with HttpRequest.read() or . Accessing the body
attribute after reading the request with either of these I/O stream methods will produce a RawPostDataException
.
HttpRequest.path
A string representing the full path to the requested page, not including the scheme, domain, or query string.
Example: "/music/bands/the_beatles/"
HttpRequest.path_info
Under some web server configurations, the portion of the URL after the host name is split up into a script prefix portion and a path info portion. The path_info
attribute always contains the path info portion of the path, no matter what web server is being used. Using this instead of path can make your code easier to move between test and deployment servers.
For example, if the WSGIScriptAlias
for your application is set to "/minfo"
, then path
might be "/minfo/music/bands/the_beatles/"
and path_info
would be "/music/bands/the_beatles/"
.
HttpRequest.method
A string representing the HTTP method used in the request. This is guaranteed to be uppercase. For example:
HttpRequest.encoding
A string representing the current encoding used to decode form submission data (or None
, which means the setting is used). You can write to this attribute to change the encoding used when accessing the form data. Any subsequent attribute accesses (such as reading from GET or ) will use the new encoding
value. Useful if you know the form data is not in the DEFAULT_CHARSET encoding.
HttpRequest.content_type
A string representing the MIME type of the request, parsed from the CONTENT_TYPE
header.
HttpRequest.content_params
A dictionary of key/value parameters included in the CONTENT_TYPE
header.
HttpRequest.GET
A dictionary-like object containing all given HTTP GET parameters. See the documentation below.
HttpRequest.POST
A dictionary-like object containing all given HTTP POST parameters, providing that the request contains form data. See the QueryDict documentation below. If you need to access raw or non-form data posted in the request, access this through the attribute instead.
It’s possible that a request can come in via POST with an empty POST
dictionary – if, say, a form is requested via the POST HTTP method but does not include form data. Therefore, you shouldn’t use if request.POST
to check for use of the POST method; instead, use if request.method == "POST"
(see HttpRequest.method).
POST
does not include file-upload information. See .
HttpRequest.COOKIES
A dictionary containing all cookies. Keys and values are strings.
HttpRequest.FILES
A dictionary-like object containing all uploaded files. Each key in FILES
is the name
from the <input type="file" name="">
. Each value in FILES
is an UploadedFile.
See for more information.
FILES
will only contain data if the request method was POST and the <form>
that posted to the request had enctype="multipart/form-data"
. Otherwise, FILES
will be a blank dictionary-like object.
HttpRequest.META
A dictionary containing all available HTTP headers. Available headers depend on the client and server, but here are some examples:
CONTENT_LENGTH
– The length of the request body (as a string).CONTENT_TYPE
– The MIME type of the request body.HTTP_ACCEPT
– Acceptable content types for the response.HTTP_ACCEPT_ENCODING
– Acceptable encodings for the response.HTTP_ACCEPT_LANGUAGE
– Acceptable languages for the response.HTTP_HOST
– The HTTP Host header sent by the client.HTTP_REFERER
– The referring page, if any.HTTP_USER_AGENT
– The client’s user-agent string.QUERY_STRING
– The query string, as a single (unparsed) string.REMOTE_ADDR
– The IP address of the client.REMOTE_HOST
– The hostname of the client.REMOTE_USER
– The user authenticated by the web server, if any.REQUEST_METHOD
– A string such as"GET"
or"POST"
.SERVER_NAME
– The hostname of the server.SERVER_PORT
– The port of the server (as a string).
With the exception of CONTENT_LENGTH
and CONTENT_TYPE
, as given above, any HTTP headers in the request are converted to META
keys by converting all characters to uppercase, replacing any hyphens with underscores and adding an HTTP_
prefix to the name. So, for example, a header called X-Bender
would be mapped to the META
key HTTP_X_BENDER
.
Note that runserver strips all headers with underscores in the name, so you won’t see them in META
. This prevents header-spoofing based on ambiguity between underscores and dashes both being normalizing to underscores in WSGI environment variables. It matches the behavior of web servers like Nginx and Apache 2.4+.
is a simpler way to access all HTTP-prefixed headers, plus CONTENT_LENGTH
and CONTENT_TYPE
.
HttpRequest.headers
A case insensitive, dict-like object that provides access to all HTTP-prefixed headers (plus Content-Length
and Content-Type
) from the request.
The name of each header is stylized with title-casing (e.g. User-Agent
) when it’s displayed. You can access headers case-insensitively:
>>> request.headers
{'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6', ...}
>>> 'User-Agent' in request.headers
True
>>> 'user-agent' in request.headers
True
>>> request.headers['User-Agent']
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
>>> request.headers['user-agent']
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
>>> request.headers.get('User-Agent')
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
>>> request.headers.get('user-agent')
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
For use in, for example, Django templates, headers can also be looked up using underscores in place of hyphens:
{{ request.headers.user_agent }}
HttpRequest.resolver_match
An instance of ResolverMatch representing the resolved URL. This attribute is only set after URL resolving took place, which means it’s available in all views but not in middleware which are executed before URL resolving takes place (you can use it in though).
Attributes set by application code
Django doesn’t set these attributes itself but makes use of them if set by your application.
HttpRequest.current_app
The template tag will use its value as the current_app
argument to reverse().
HttpRequest.urlconf
This will be used as the root URLconf for the current request, overriding the setting. See How Django processes a request for details.
urlconf
can be set to None
to revert any changes made by previous middleware and return to using the .
HttpRequest.exception_reporter_filter
This will be used instead of DEFAULT_EXCEPTION_REPORTER_FILTER for the current request. See for details.
HttpRequest.exception_reporter_class
This will be used instead of DEFAULT_EXCEPTION_REPORTER for the current request. See for details.
Attributes set by middleware
Some of the middleware included in Django’s contrib apps set attributes on the request. If you don’t see the attribute on a request, be sure the appropriate middleware class is listed in .
HttpRequest.session
From the SessionMiddleware: A readable and writable, dictionary-like object that represents the current session.
HttpRequest.site
From the : An instance of Site or as returned by get_current_site() representing the current site.
HttpRequest.user
From the : An instance of AUTH_USER_MODEL representing the currently logged-in user. If the user isn’t currently logged in, user
will be set to an instance of . You can tell them apart with is_authenticated, like so:
... # Do something for logged-in users.
else:
... # Do something for anonymous users.
Methods
HttpRequest.get_host
()
Returns the originating host of the request using information from the HTTP_X_FORWARDED_HOST
(if USE_X_FORWARDED_HOST is enabled) and HTTP_HOST
headers, in that order. If they don’t provide a value, the method uses a combination of SERVER_NAME
and SERVER_PORT
as detailed in .
Example: "127.0.0.1:8000"
Raises django.core.exceptions.DisallowedHost
if the host is not in ALLOWED_HOSTS or the domain name is invalid according to /1035.
Note
The method fails when the host is behind multiple proxies. One solution is to use middleware to rewrite the proxy headers, as in the following example:
class MultipleProxyMiddleware:
FORWARDED_FOR_FIELDS = [
'HTTP_X_FORWARDED_FOR',
'HTTP_X_FORWARDED_HOST',
'HTTP_X_FORWARDED_SERVER',
]
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
"""
Rewrites the proxy headers so that only the most
recent proxy is used.
"""
for field in self.FORWARDED_FOR_FIELDS:
if field in request.META:
if ',' in request.META[field]:
parts = request.META[field].split(',')
request.META[field] = parts[-1].strip()
return self.get_response(request)
This middleware should be positioned before any other middleware that relies on the value of get_host() – for instance, or CsrfViewMiddleware.
HttpRequest.get_port
()
Returns the originating port of the request using information from the HTTP_X_FORWARDED_PORT
(if is enabled) and SERVER_PORT
META
variables, in that order.
HttpRequest.get_full_path
()
Returns the path
, plus an appended query string, if applicable.
Example: "/music/bands/the_beatles/?print=true"
HttpRequest.get_full_path_info
()
Like get_full_path(), but uses instead of path.
Example: "/minfo/music/bands/the_beatles/?print=true"
HttpRequest.build_absolute_uri
(location=None)
Returns the absolute URI form of location
. If no location is provided, the location will be set to request.get_full_path()
.
If the location is already an absolute URI, it will not be altered. Otherwise the absolute URI is built using the server variables available in this request. For example:
>>> request.build_absolute_uri()
'https://example.com/music/bands/the_beatles/?print=true'
>>> request.build_absolute_uri('/bands/')
'https://example.com/bands/'
>>> request.build_absolute_uri('https://example2.com/bands/')
'https://example2.com/bands/'
Note
Mixing HTTP and HTTPS on the same site is discouraged, therefore will always generate an absolute URI with the same scheme the current request has. If you need to redirect users to HTTPS, it’s best to let your web server redirect all HTTP traffic to HTTPS.
HttpRequest.get_signed_cookie
(key, default=RAISE_ERROR, salt=’’, max_age=None)
Returns a cookie value for a signed cookie, or raises a django.core.signing.BadSignature
exception if the signature is no longer valid. If you provide the default
argument the exception will be suppressed and that default value will be returned instead.
The optional salt
argument can be used to provide extra protection against brute force attacks on your secret key. If supplied, the argument will be checked against the signed timestamp attached to the cookie value to ensure the cookie is not older than max_age
seconds.
For example:
>>> request.get_signed_cookie('name')
'Tony'
>>> request.get_signed_cookie('name', salt='name-salt')
'Tony' # assuming cookie was set using the same salt
>>> request.get_signed_cookie('nonexistent-cookie')
...
KeyError: 'nonexistent-cookie'
>>> request.get_signed_cookie('nonexistent-cookie', False)
False
>>> request.get_signed_cookie('cookie-that-was-tampered-with')
...
BadSignature: ...
>>> request.get_signed_cookie('name', max_age=60)
...
SignatureExpired: Signature age 1677.3839159 > 60 seconds
>>> request.get_signed_cookie('name', False, max_age=60)
False
See cryptographic signing for more information.
HttpRequest.is_secure
()
Returns True
if the request is secure; that is, if it was made with HTTPS.
HttpRequest.accepts
(mime_type)
Returns True
if the request Accept
header matches the mime_type
argument:
>>> request.accepts('text/html')
True
Most browsers send Accept: */*
by default, so this would return True
for all content types. Setting an explicit Accept
header in API requests can be useful for returning a different content type for those consumers only. See of using accepts()
to return different content to API consumers.
If a response varies depending on the content of the Accept
header and you are using some form of caching like Django’s cache middleware, you should decorate the view with so that the responses are properly cached.
HttpRequest.read
(size=None)
HttpRequest.readline
()
HttpRequest.readlines
()
HttpRequest.__iter__
()
Methods implementing a file-like interface for reading from an HttpRequest
instance. This makes it possible to consume an incoming request in a streaming fashion. A common use-case would be to process a big XML payload with an iterative parser without constructing a whole XML tree in memory.
Given this standard interface, an HttpRequest
instance can be passed directly to an XML parser such as ElementTree:
import xml.etree.ElementTree as ET
for element in ET.iterparse(request):
process(element)
class QueryDict
In an object, the GET and attributes are instances of django.http.QueryDict
, a dictionary-like class customized to deal with multiple values for the same key. This is necessary because some HTML form elements, notably <select multiple>
, pass multiple values for the same key.
QueryDict implements all the standard dictionary methods because it’s a subclass of dictionary. Exceptions are outlined here:
QueryDict.__init__
(query_string=None, mutable=False, encoding=None)
Instantiates a QueryDict
object based on query_string
.
>>> QueryDict('a=1&a=2&c=3')
<QueryDict: {'a': ['1', '2'], 'c': ['3']}>
If query_string
is not passed in, the resulting QueryDict
will be empty (it will have no keys or values).
Most QueryDict
s you encounter, and in particular those at request.POST
and request.GET
, will be immutable. If you are instantiating one yourself, you can make it mutable by passing mutable=True
to its __init__()
.
Strings for setting both keys and values will be converted from encoding
to str
. If encoding
is not set, it defaults to .
classmethod QueryDict.fromkeys
(iterable, value=’’, mutable=False, encoding=None)
Creates a new QueryDict
with keys from iterable
and each value equal to value
. For example:
QueryDict.__getitem__
(key)
Returns the value for the given key. If the key has more than one value, it returns the last value. Raises django.utils.datastructures.MultiValueDictKeyError
if the key does not exist. (This is a subclass of Python’s standard KeyError, so you can stick to catching KeyError
.)
QueryDict.__setitem__
(key, value)
Sets the given key to [value]
(a list whose single element is value
). Note that this, as other dictionary functions that have side effects, can only be called on a mutable QueryDict
(such as one that was created via ).
QueryDict.__contains__
(key)
Returns True
if the given key is set. This lets you do, e.g., if "foo" in request.GET
.
QueryDict.get
(key, default=None)
Uses the same logic as __getitem__(), with a hook for returning a default value if the key doesn’t exist.
QueryDict.setdefault
(key, default=None)
Like , except it uses __setitem__() internally.
QueryDict.update
(other_dict)
Takes either a QueryDict
or a dictionary. Like , except it appends to the current dictionary items rather than replacing them. For example:
>>> q = QueryDict('a=1', mutable=True)
>>> q.update({'a': '2'})
>>> q.getlist('a')
['1', '2']
>>> q['a'] # returns the last
'2'
QueryDict.items
()
Like dict.items(), except this uses the same last-value logic as and returns an iterator object instead of a view object. For example:
>>> list(q.items())
[('a', '3')]
QueryDict.values
()
Like dict.values(), except this uses the same last-value logic as and returns an iterator instead of a view object. For example:
>>> q = QueryDict('a=1&a=2&a=3')
>>> list(q.values())
['3']
In addition, QueryDict
has the following methods:
QueryDict.copy
()
Returns a copy of the object using copy.deepcopy(). This copy will be mutable even if the original was not.
QueryDict.getlist
(key, default=None)
Returns a list of the data with the requested key. Returns an empty list if the key doesn’t exist and default
is None
. It’s guaranteed to return a list unless the default value provided isn’t a list.
QueryDict.setlist
(key, list_)
Sets the given key to list_
(unlike ).
QueryDict.appendlist
(key, item)
Appends an item to the internal list associated with key.
QueryDict.setlistdefault
(key, default_list=None)
Like setdefault(), except it takes a list of values instead of a single value.
QueryDict.lists
()
Like , except it includes all values, as a list, for each member of the dictionary. For example:
>>> q = QueryDict('a=1&a=2&a=3')
>>> q.lists()
[('a', ['1', '2', '3'])]
QueryDict.pop
(key)
Returns a list of values for the given key and removes them from the dictionary. Raises KeyError
if the key does not exist. For example:
>>> q = QueryDict('a=1&a=2&a=3', mutable=True)
>>> q.pop('a')
['1', '2', '3']
QueryDict.popitem
()
Removes an arbitrary member of the dictionary (since there’s no concept of ordering), and returns a two value tuple containing the key and a list of all values for the key. Raises KeyError
when called on an empty dictionary. For example:
>>> q = QueryDict('a=1&a=2&a=3', mutable=True)
>>> q.popitem()
('a', ['1', '2', '3'])
QueryDict.dict
()
Returns a dict
representation of QueryDict
. For every (key, list) pair in QueryDict
, dict
will have (key, item), where item is one element of the list, using the same logic as QueryDict.__getitem__():
>>> q = QueryDict('a=1&a=3&a=5')
>>> q.dict()
{'a': '5'}
QueryDict.urlencode
(safe=None)
Returns a string of the data in query string format. For example:
>>> q = QueryDict('a=2&b=3&b=5')
>>> q.urlencode()
'a=2&b=3&b=5'
Use the safe
parameter to pass characters which don’t require encoding. For example:
>>> q = QueryDict(mutable=True)
>>> q['next'] = '/a&b/'
>>> q.urlencode(safe='/')
'next=/a%26b/'
HttpResponse
objects
class HttpResponse
In contrast to HttpRequest objects, which are created automatically by Django, objects are your responsibility. Each view you write is responsible for instantiating, populating, and returning an HttpResponse.
The class lives in the django.http module.
Usage
Passing strings
Typical usage is to pass the contents of the page, as a string, bytestring, or , to the HttpResponse constructor:
But if you want to add content incrementally, you can use response
as a file-like object:
>>> response = HttpResponse()
>>> response.write("<p>Here's the text of the web page.</p>")
>>> response.write("<p>Here's another paragraph.</p>")
Passing iterators
Finally, you can pass HttpResponse
an iterator rather than strings. HttpResponse
will consume the iterator immediately, store its content as a string, and discard it. Objects with a close()
method such as files and generators are immediately closed.
If you need the response to be streamed from the iterator to the client, you must use the StreamingHttpResponse class instead.
Setting header fields
To set or remove a header field in your response, use HttpResponse.headers:
>>> response = HttpResponse()
>>> response.headers['Age'] = 120
>>> del response.headers['Age']
You can also manipulate headers by treating your response like a dictionary:
>>> response = HttpResponse()
>>> response['Age'] = 120
>>> del response['Age']
This proxies to HttpResponse.headers
, and is the original interface offered by HttpResponse
.
When using this interface, unlike a dictionary, del
doesn’t raise KeyError
if the header field doesn’t exist.
You can also set headers on instantiation:
>>> response = HttpResponse(headers={'Age': 120})
For setting the Cache-Control
and Vary
header fields, it is recommended to use the and patch_vary_headers() methods from , since these fields can have multiple, comma-separated values. The “patch” methods ensure that other values, e.g. added by a middleware, are not removed.
HTTP header fields cannot contain newlines. An attempt to set a header field containing a newline character (CR or LF) will raise BadHeaderError
Telling the browser to treat the response as a file attachment
To tell the browser to treat the response as a file attachment, set the Content-Type
and Content-Disposition
headers. For example, this is how you might return a Microsoft Excel spreadsheet:
>>> response = HttpResponse(my_data, headers={
... 'Content-Type': 'application/vnd.ms-excel',
... 'Content-Disposition': 'attachment; filename="foo.xls"',
... })
There’s nothing Django-specific about the Content-Disposition
header, but it’s easy to forget the syntax, so we’ve included it here.
Attributes
HttpResponse.content
A bytestring representing the content, encoded from a string if necessary.
HttpResponse.headers
A case insensitive, dict-like object that provides an interface to all HTTP headers on the response. See Setting header fields.
A string denoting the charset in which the response will be encoded. If not given at HttpResponse
instantiation time, it will be extracted from content_type
and if that is unsuccessful, the setting will be used.
HttpResponse.status_code
The HTTP status code for the response.
Unless is explicitly set, modifying the value of status_code
outside the constructor will also modify the value of reason_phrase
.
HttpResponse.reason_phrase
The HTTP reason phrase for the response. It uses the HTTP standard’s default reason phrases.
Unless explicitly set, reason_phrase
is determined by the value of .
HttpResponse.streaming
This is always False
.
This attribute exists so middleware can treat streaming responses differently from regular responses.
HttpResponse.closed
True
if the response has been closed.
Methods
HttpResponse.__init__
(content=b’’, content_type=None, status=200, reason=None, charset=None, headers=None)
Instantiates an HttpResponse
object with the given page content, content type, and headers.
content
is most commonly an iterator, bytestring, , or string. Other types will be converted to a bytestring by encoding their string representation. Iterators should return strings or bytestrings and those will be joined together to form the content of the response.
content_type
is the MIME type optionally completed by a character set encoding and is used to fill the HTTP Content-Type
header. If not specified, it is formed by 'text/html'
and the DEFAULT_CHARSET settings, by default: "text/html; charset=utf-8"
.
status
is the for the response. You can use Python’s http.HTTPStatus for meaningful aliases, such as HTTPStatus.NO_CONTENT
.
reason
is the HTTP response phrase. If not provided, a default phrase will be used.
charset
is the charset in which the response will be encoded. If not given it will be extracted from content_type
, and if that is unsuccessful, the setting will be used.
headers
is a dict of HTTP headers for the response.
HttpResponse.__setitem__
(header, value)
Sets the given header name to the given value. Both header
and value
should be strings.
HttpResponse.__delitem__
(header)
Deletes the header with the given name. Fails silently if the header doesn’t exist. Case-insensitive.
HttpResponse.__getitem__
(header)
Returns the value for the given header name. Case-insensitive.
HttpResponse.get
(header, alternate=None)
Returns the value for the given header, or an alternate
if the header doesn’t exist.
HttpResponse.has_header
(header)
Returns True
or False
based on a case-insensitive check for a header with the given name.
HttpResponse.items
()
Acts like for HTTP headers on the response.
HttpResponse.setdefault
(header, value)
Sets a header unless it has already been set.
HttpResponse.set_cookie
(key, value=’’, max_age=None, expires=None, path=’/‘, domain=None, secure=False, httponly=False, samesite=None)
max_age
should be a timedelta object, an integer number of seconds, orNone
(default) if the cookie should last only as long as the client’s browser session. Ifexpires
is not specified, it will be calculated.Changed in Django 4.1:
Support for
timedelta
objects was added.expires
should either be a string in the format"Wdy, DD-Mon-YY HH:MM:SS GMT"
or adatetime.datetime
object in UTC. Ifexpires
is adatetime
object, themax_age
will be calculated.Use
domain
if you want to set a cross-domain cookie. For example,domain="example.com"
will set a cookie that is readable by the domains www.example.com, blog.example.com, etc. Otherwise, a cookie will only be readable by the domain that set it.Use
secure=True
if you want the cookie to be only sent to the server when a request is made with thehttps
scheme.Use
httponly=True
if you want to prevent client-side JavaScript from having access to the cookie.is a flag included in a Set-Cookie HTTP response header. It’s part of the RFC 6265 standard for cookies and can be a useful way to mitigate the risk of a client-side script accessing the protected cookie data.
Use
samesite='Strict'
orsamesite='Lax'
to tell the browser not to send this cookie when performing a cross-origin request. isn’t supported by all browsers, so it’s not a replacement for Django’s CSRF protection, but rather a defense in depth measure.Use
samesite='None'
(string) to explicitly state that this cookie is sent with all same-site and cross-site requests.
Warning
RFC 6265 states that user agents should support cookies of at least 4096 bytes. For many browsers this is also the maximum size. Django will not raise an exception if there’s an attempt to store a cookie of more than 4096 bytes, but many browsers will not set the cookie correctly.
HttpResponse.set_signed_cookie
(key, value, salt=’’, max_age=None, expires=None, path=’/‘, domain=None, secure=False, httponly=False, samesite=None)
Like , but cryptographic signing the cookie before setting it. Use in conjunction with . You can use the optional salt
argument for added key strength, but you will need to remember to pass it to the corresponding HttpRequest.get_signed_cookie() call.
HttpResponse.delete_cookie
(key, path=’/‘, domain=None, samesite=None)
Deletes the cookie with the given key. Fails silently if the key doesn’t exist.
Due to the way cookies work, path
and domain
should be the same values you used in set_cookie()
– otherwise the cookie may not be deleted.
HttpResponse.close
()
This method is called at the end of the request directly by the WSGI server.
HttpResponse.write
(content)
This method makes an instance a file-like object.
HttpResponse.flush
()
This method makes an HttpResponse instance a file-like object.
HttpResponse.tell
()
This method makes an instance a file-like object.
HttpResponse.getvalue
()
Returns the value of HttpResponse.content. This method makes an instance a stream-like object.
HttpResponse.readable
()
Always False
. This method makes an HttpResponse instance a stream-like object.
HttpResponse.seekable
()
Always False
. This method makes an instance a stream-like object.
HttpResponse.writable
()
Always True
. This method makes an HttpResponse instance a stream-like object.
HttpResponse.writelines
(lines)
Writes a list of lines to the response. Line separators are not added. This method makes an instance a stream-like object.
Django includes a number of HttpResponse
subclasses that handle different types of HTTP responses. Like HttpResponse
, these subclasses live in django.http.
class HttpResponseRedirect
The first argument to the constructor is required – the path to redirect to. This can be a fully qualified URL (e.g. 'https://www.yahoo.com/search/'
), an absolute path with no domain (e.g. '/search/'
), or even a relative path (e.g. 'search/'
). In that last case, the client browser will reconstruct the full URL itself according to the current path. See for other optional constructor arguments. Note that this returns an HTTP status code 302.
url
This read-only attribute represents the URL the response will redirect to (equivalent to the
Location
response header).
class HttpResponsePermanentRedirect
Like HttpResponseRedirect, but it returns a permanent redirect (HTTP status code 301) instead of a “found” redirect (status code 302).
class HttpResponseNotModified
The constructor doesn’t take any arguments and no content should be added to this response. Use this to designate that a page hasn’t been modified since the user’s last request (status code 304).
class HttpResponseBadRequest
Acts just like but uses a 400 status code.
class HttpResponseNotFound
Acts just like HttpResponse but uses a 404 status code.
class HttpResponseForbidden
Acts just like but uses a 403 status code.
class HttpResponseNotAllowed
Like HttpResponse, but uses a 405 status code. The first argument to the constructor is required: a list of permitted methods (e.g. ['GET', 'POST']
).
class HttpResponseGone
Acts just like but uses a 410 status code.
class HttpResponseServerError
Acts just like HttpResponse but uses a 500 status code.
Note
If a custom subclass of implements a render
method, Django will treat it as emulating a SimpleTemplateResponse, and the render
method must itself return a valid response object.
Custom response classes
If you find yourself needing a response class that Django doesn’t provide, you can create it with the help of http.HTTPStatus. For example:
from http import HTTPStatus
from django.http import HttpResponse
class HttpResponseNoContent(HttpResponse):
status_code = HTTPStatus.NO_CONTENT
class JsonResponse
(data, encoder=DjangoJSONEncoder, safe=True, json_dumps_params=None, \*kwargs*)
An subclass that helps to create a JSON-encoded response. It inherits most behavior from its superclass with a couple differences:
Its default Content-Type
header is set to application/json.
The first parameter, data
, should be a dict
instance. If the safe
parameter is set to False
(see below) it can be any JSON-serializable object.
The encoder
, which defaults to django.core.serializers.json.DjangoJSONEncoder, will be used to serialize the data. See for more details about this serializer.
The safe
boolean parameter defaults to True
. If it’s set to False
, any object can be passed for serialization (otherwise only dict
instances are allowed). If safe
is True
and a non-dict
object is passed as the first argument, a TypeError will be raised.
The json_dumps_params
parameter is a dictionary of keyword arguments to pass to the json.dumps()
call used to generate the response.
Usage
Typical usage could look like:
>>> from django.http import JsonResponse
>>> response = JsonResponse({'foo': 'bar'})
>>> response.content
b'{"foo": "bar"}'
Serializing non-dictionary objects
In order to serialize objects other than dict
you must set the safe
parameter to False
:
>>> response = JsonResponse([1, 2, 3], safe=False)
Without passing safe=False
, a will be raised.
Note that an API based on dict
objects is more extensible, flexible, and makes it easier to maintain forwards compatibility. Therefore, you should avoid using non-dict objects in JSON-encoded response.
Warning
Before the 5th edition of ECMAScript it was possible to poison the JavaScript Array
constructor. For this reason, Django does not allow passing non-dict objects to the constructor by default. However, most modern browsers implement ECMAScript 5 which removes this attack vector. Therefore it is possible to disable this security precaution.
Changing the default JSON encoder
If you need to use a different JSON encoder class you can pass the encoder
parameter to the constructor method:
>>> response = JsonResponse(data, encoder=MyJSONEncoder)
StreamingHttpResponse
objects
class StreamingHttpResponse
The StreamingHttpResponse class is used to stream a response from Django to the browser. You might want to do this if generating the response takes too long or uses too much memory. For instance, it’s useful for .
Performance considerations
Django is designed for short-lived requests. Streaming responses will tie a worker process for the entire duration of the response. This may result in poor performance.
Generally speaking, you should perform expensive tasks outside of the request-response cycle, rather than resorting to a streamed response.
The StreamingHttpResponse is not a subclass of , because it features a slightly different API. However, it is almost identical, with the following notable differences:
- It should be given an iterator that yields bytestrings as content.
- You cannot access its content, except by iterating the response object itself. This should only occur when the response is returned to the client.
- It has no
content
attribute. Instead, it has a streaming_content attribute. - You cannot use the file-like object
tell()
orwrite()
methods. Doing so will raise an exception.
should only be used in situations where it is absolutely required that the whole content isn’t iterated before transferring the data to the client. Because the content can’t be accessed, many middleware can’t function normally. For example the ETag
and Content-Length
headers can’t be generated for streaming responses.
The HttpResponseBase base class is common between and StreamingHttpResponse.
Attributes
StreamingHttpResponse.streaming_content
An iterator of the response content, bytestring encoded according to HttpResponse.charset.
StreamingHttpResponse.status_code
The for the response.
Unless reason_phrase is explicitly set, modifying the value of status_code
outside the constructor will also modify the value of reason_phrase
.
StreamingHttpResponse.reason_phrase
The HTTP reason phrase for the response. It uses the default reason phrases.
Unless explicitly set, reason_phrase
is determined by the value of status_code.
StreamingHttpResponse.streaming
This is always True
.
class FileResponse
(open_file, as_attachment=False, filename=’’, \*kwargs*)
is a subclass of StreamingHttpResponse optimized for binary files. It uses if provided by the wsgi server, otherwise it streams the file out in small chunks.
If as_attachment=True
, the Content-Disposition
header is set to attachment
, which asks the browser to offer the file to the user as a download. Otherwise, a Content-Disposition
header with a value of inline
(the browser default) will be set only if a filename is available.
If open_file
doesn’t have a name or if the name of open_file
isn’t appropriate, provide a custom file name using the filename
parameter. Note that if you pass a file-like object like io.BytesIO
, it’s your task to seek()
it before passing it to FileResponse
.
The Content-Length
and Content-Type
headers are automatically set when they can be guessed from contents of open_file
.
FileResponse
accepts any file-like object with binary content, for example a file open in binary mode like so:
The file will be closed automatically, so don’t open it with a context manager.
Methods
FileResponse.set_headers
(open_file)
This method is automatically called during the response initialization and set various headers (Content-Length
, Content-Type
, and Content-Disposition
) depending on open_file
.
HttpResponseBase
class
class
The HttpResponseBase class is common to all Django responses. It should not be used to create responses directly, but it can be useful for type-checking.