Django uses request and response objects to pass state through the system.
When a page is requested, Django creates an HttpRequest
object that
contains metadata about the request. Then Django loads the appropriate view,
passing the HttpRequest
as the first argument to the view function.
Each view is responsible for returning an HttpResponse
object.
This document explains the APIs for HttpRequest
and
HttpResponse
objects, which are defined in the django.http
module.
HttpRequest
objects¶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
HttpRequest.POST
.
You can also read from an HttpRequest
using a file-like interface. See
HttpRequest.read()
.
HttpRequest.
path
¶A string representing the full path to the requested page, not including the scheme or domain.
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:
if request.method == 'GET':
do_something()
elif request.method == 'POST':
do_something_else()
HttpRequest.
encoding
¶A string representing the current encoding used to decode form submission
data (or None
, which means the DEFAULT_CHARSET
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 POST
) 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
QueryDict
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
HttpRequest.body
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 FILES
.
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 Managing files 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+.
HttpRequest.headers
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)
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
process_view()
though).
Django doesn’t set these attributes itself but makes use of them if set by your application.
HttpRequest.
current_app
¶The url
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 ROOT_URLCONF
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 ROOT_URLCONF
.
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 MIDDLEWARE
.
HttpRequest.
session
¶From the SessionMiddleware
: A
readable and writable, dictionary-like object that represents the current
session.
HttpRequest.
site
¶From the CurrentSiteMiddleware
:
An instance of Site
or
RequestSite
as returned by
get_current_site()
representing the current site.
HttpRequest.
user
¶From the AuthenticationMiddleware
:
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 AnonymousUser
. You
can tell them apart with
is_authenticated
, like so:
if request.user.is_authenticated:
... # Do something for logged-in users.
else:
... # Do something for anonymous users.
HttpRequest.
get_host
()[source]¶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 PEP 3333.
Example: "127.0.0.1:8000"
Note
The get_host()
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,
CommonMiddleware
or
CsrfViewMiddleware
.
HttpRequest.
get_port
()[source]¶Returns the originating port of the request using information from the
HTTP_X_FORWARDED_PORT
(if USE_X_FORWARDED_PORT
is enabled)
and SERVER_PORT
META
variables, in that order.
HttpRequest.
get_full_path
()[source]¶Returns the path
, plus an appended query string, if applicable.
Example: "/music/bands/the_beatles/?print=true"
HttpRequest.
get_full_path_info
()[source]¶Like get_full_path()
, but uses path_info
instead of
path
.
Example: "/minfo/music/bands/the_beatles/?print=true"
HttpRequest.
build_absolute_uri
(location=None)[source]¶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
build_absolute_uri()
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.
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
max_age
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
()[source]¶Returns True
if the request is secure; that is, if it was made with
HTTPS.
HttpRequest.
is_ajax
()[source]¶Returns True
if the request was made via an XMLHttpRequest
, by
checking the HTTP_X_REQUESTED_WITH
header for the string
'XMLHttpRequest'
. Most modern JavaScript libraries send this header.
If you write your own XMLHttpRequest
call (on the browser side), you’ll
have to set this header manually if you want is_ajax()
to work.
If a response varies on whether or not it’s requested via AJAX and you are
using some form of caching like Django’s cache middleware
, you should decorate the view with
vary_on_headers('X-Requested-With')
so that the responses are
properly cached.
HttpRequest.
__iter__
()[source]¶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)
QueryDict
objects¶In an HttpRequest
object, the GET
and
POST
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.
The QueryDict
s at request.POST
and request.GET
will be immutable
when accessed in a normal request/response cycle. To get a mutable version you
need to use QueryDict.copy()
.
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)[source]¶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
DEFAULT_CHARSET
.
QueryDict.
fromkeys
(iterable, value='', mutable=False, encoding=None)[source]¶Creates a new QueryDict
with keys from iterable
and each value
equal to value
. For example:
>>> QueryDict.fromkeys(['a', 'a', 'b'], value='val')
<QueryDict: {'a': ['val', 'val'], 'b': ['val']}>
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)[source]¶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.copy()
).
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)[source]¶Like dict.setdefault()
, except it uses __setitem__()
internally.
QueryDict.
update
(other_dict)¶Takes either a QueryDict
or a dictionary. Like dict.update()
,
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
__getitem__()
and returns an iterator object instead of a view object.
For example:
>>> q = QueryDict('a=1&a=2&a=3')
>>> list(q.items())
[('a', '3')]
QueryDict.
values
()¶Like dict.values()
, except this uses the same last-value logic as
__getitem__()
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
()[source]¶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 a default value wasn’t provided. It’s guaranteed to return a list unless the default value provided isn’t a list.
QueryDict.
setlist
(key, list_)[source]¶Sets the given key to list_
(unlike __setitem__()
).
QueryDict.
setlistdefault
(key, default_list=None)[source]¶Like setdefault()
, except it takes a list of values instead of a
single value.
QueryDict.
lists
()¶Like items()
, 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)[source]¶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
()[source]¶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)[source]¶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¶In contrast to HttpRequest
objects, which are created automatically by
Django, HttpResponse
objects are your responsibility. Each view you
write is responsible for instantiating, populating, and returning an
HttpResponse
.
The HttpResponse
class lives in the django.http
module.
Typical usage is to pass the contents of the page, as a string or bytestring,
to the HttpResponse
constructor:
>>> from django.http import HttpResponse
>>> response = HttpResponse("Here's the text of the Web page.")
>>> response = HttpResponse("Text only, please.", content_type="text/plain")
>>> response = HttpResponse(b'Bytestrings are also accepted.')
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>")
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.
To set or remove a header field in your response, treat it like a dictionary:
>>> response = HttpResponse()
>>> response['Age'] = 120
>>> del response['Age']
Note that unlike a dictionary, del
doesn’t raise KeyError
if the header
field doesn’t exist.
For setting the Cache-Control
and Vary
header fields, it is recommended
to use the patch_cache_control()
and
patch_vary_headers()
methods from
django.utils.cache
, 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
To tell the browser to treat the response as a file attachment, use the
content_type
argument and set the Content-Disposition
header. For example,
this is how you might return a Microsoft Excel spreadsheet:
>>> response = HttpResponse(my_data, content_type='application/vnd.ms-excel')
>>> response['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.
HttpResponse.
content
¶A bytestring representing the content, encoded from a string if necessary.
HttpResponse.
charset
¶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
DEFAULT_CHARSET
setting will be used.
HttpResponse.
status_code
¶The HTTP status code 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
.
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
status_code
.
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.
HttpResponse.
__init__
(content=b'', content_type=None, status=200, reason=None, charset=None)[source]¶Instantiates an HttpResponse
object with the given page content and
content type.
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 the DEFAULT_CONTENT_TYPE
and
DEFAULT_CHARSET
settings, by default: “text/html; charset=utf-8”.
status
is the HTTP status code 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 DEFAULT_CHARSET
setting will be used.
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.
has_header
(header)¶Returns True
or False
based on a case-insensitive check for a
header with the given name.
HttpResponse.
setdefault
(header, value)¶Sets a header unless it has already been set.
Sets a cookie. The parameters are the same as in the
Morsel
cookie object in the Python standard library.
max_age
should be a number of seconds, or None
(default) if
the cookie should last only as long as the client’s browser session.
If expires
is not specified, it will be calculated.
expires
should either be a string in the format
"Wdy, DD-Mon-YY HH:MM:SS GMT"
or a datetime.datetime
object
in UTC. If expires
is a datetime
object, the max_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 httponly=True
if you want to prevent client-side
JavaScript from having access to the cookie.
HttpOnly 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'
or samesite='Lax'
to tell the browser not
to send this cookie when performing a cross-origin request. SameSite
isn’t supported by all browsers, so it’s not a replacement for Django’s
CSRF protection, but rather a defense in depth measure.
The samesite
argument was added.
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.
Like set_cookie()
, but
cryptographic signing the cookie before setting
it. Use in conjunction with HttpRequest.get_signed_cookie()
.
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.
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.
The samesite
argument was added.
HttpResponse.
close
()¶This method is called at the end of the request directly by the WSGI server.
HttpResponse.
write
(content)[source]¶This method makes an HttpResponse
instance a file-like object.
HttpResponse.
flush
()¶This method makes an HttpResponse
instance a file-like object.
HttpResponse.
tell
()[source]¶This method makes an HttpResponse
instance a file-like object.
HttpResponse.
getvalue
()[source]¶Returns the value of HttpResponse.content
. This method makes
an HttpResponse
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 HttpResponse
instance a
stream-like object.
HttpResponse.
writable
()[source]¶Always True
. This method makes an HttpResponse
instance a
stream-like object.
HttpResponse.
writelines
(lines)[source]¶Writes a list of lines to the response. Line separators are not added. This
method makes an HttpResponse
instance a stream-like object.
HttpResponse
subclasses¶Django includes a number of HttpResponse
subclasses that handle different
types of HTTP responses. Like HttpResponse
, these subclasses live in
django.http
.
HttpResponseRedirect
[source]¶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 HttpResponse
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).
HttpResponsePermanentRedirect
[source]¶Like HttpResponseRedirect
, but it returns a permanent redirect
(HTTP status code 301) instead of a “found” redirect (status code 302).
HttpResponseNotModified
[source]¶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).
HttpResponseBadRequest
[source]¶Acts just like HttpResponse
but uses a 400 status code.
HttpResponseNotFound
[source]¶Acts just like HttpResponse
but uses a 404 status code.
HttpResponseForbidden
[source]¶Acts just like HttpResponse
but uses a 403 status code.
HttpResponseNotAllowed
[source]¶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']
).
HttpResponseGone
[source]¶Acts just like HttpResponse
but uses a 410 status code.
HttpResponseServerError
[source]¶Acts just like HttpResponse
but uses a 500 status code.
Note
If a custom subclass of HttpResponse
implements a render
method, Django will treat it as emulating a
SimpleTemplateResponse
, and the
render
method must itself return a valid response object.
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
JsonResponse
objects¶JsonResponse
(data, encoder=DjangoJSONEncoder, safe=True, json_dumps_params=None, **kwargs)[source]¶An HttpResponse
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 JSON serialization 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.
Typical usage could look like:
>>> from django.http import JsonResponse
>>> response = JsonResponse({'foo': 'bar'})
>>> response.content
b'{"foo": "bar"}'
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 TypeError
will be raised.
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
JsonResponse
constructor by default. However, most
modern browsers implement EcmaScript 5 which removes this attack vector.
Therefore it is possible to disable this security precaution.
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¶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
generating large CSV files.
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 HttpResponse
,
because it features a slightly different API. However, it is almost identical,
with the following notable differences:
content
attribute. Instead, it has a
streaming_content
attribute.tell()
or write()
methods.
Doing so will raise an exception.StreamingHttpResponse
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.
StreamingHttpResponse.
streaming_content
¶An iterator of the response content, bytestring encoded according to
HttpResponse.charset
.
StreamingHttpResponse.
status_code
¶The HTTP status code 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 HTTP standard’s default reason phrases.
Unless explicitly set, reason_phrase
is determined by the value of
status_code
.
StreamingHttpResponse.
streaming
¶This is always True
.
FileResponse
objects¶FileResponse
(open_file, as_attachment=False, filename='', **kwargs)[source]¶FileResponse
is a subclass of StreamingHttpResponse
optimized for binary files. It uses wsgi.file_wrapper 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, which
asks the browser to offer the file to the user as a download.
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
, Content-Type
, and Content-Disposition
headers are automatically set when they can be guessed from contents of
open_file
.
The as_attachment
and filename
keywords argument were added.
Also, FileResponse
sets the Content
headers if it can guess
them.
FileResponse
accepts any file-like object with binary content, for example
a file open in binary mode like so:
>>> from django.http import FileResponse
>>> response = FileResponse(open('myfile.png', 'rb'))
The file will be closed automatically, so don’t open it with a context manager.
Nov 02, 2020