Request and response objects

Quick overview

Django uses request and response objects to pass state through the system.

When a page is requested, Django creates an HttpRequest object thatcontains 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 andHttpResponse objects, which are defined in the django.httpmodule.

HttpRequest objects

属性

All attributes should be considered read-only, unless stated otherwise.

  • HttpRequest.scheme

  • A string representing the scheme of the request (http or httpsusually).

  • HttpRequest.body

  • The raw HTTP request body as a bytestring. This is useful for processingdata in different ways than conventional HTML forms: binary images,XML payload etc. For processing conventional form data, useHttpRequest.POST.

You can also read from an HttpRequest using a file-like interface. SeeHttpRequest.read().

  • HttpRequest.path
  • A string representing the full path to the requested page, not includingthe scheme or domain.

Example: "/music/bands/the_beatles/"

  • HttpRequest.path_info
  • Under some Web server configurations, the portion of the URL after thehost name is split up into a script prefix portion and a path infoportion. The path_info attribute always contains the path info portionof the path, no matter what Web server is being used. Using this insteadof path can make your code easier to move betweentest 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 isguaranteed to be uppercase. For example:
  1. if request.method == 'GET':
  2.     do_something()
  3. elif request.method == 'POST':
  4.     do_something_else()
  • HttpRequest.encoding

  • A string representing the current encoding used to decode form submissiondata (or None, which means the DEFAULT_CHARSET setting isused). You can write to this attribute to change the encoding used whenaccessing the form data. Any subsequent attribute accesses (such as readingfrom GET or POST) will use the new encoding value.Useful if you know the form data is not in the DEFAULT_CHARSETencoding.

  • HttpRequest.content_type

  • A string representing the MIME type of the request, parsed from theCONTENT_TYPE header.

  • HttpRequest.content_params

  • A dictionary of key/value parameters included in the CONTENT_TYPEheader.

  • HttpRequest.GET

  • A dictionary-like object containing all given HTTP GET parameters. See theQueryDict documentation below.

  • HttpRequest.POST

  • A dictionary-like object containing all given HTTP POST parameters,providing that the request contains form data. See theQueryDict documentation below. If you need to access raw ornon-form data posted in the request, access this through theHttpRequest.body attribute instead.

It's possible that a request can come in via POST with an empty POSTdictionary — if, say, a form is requested via the POST HTTP method butdoes not include form data. Therefore, you shouldn't use if request.POSTto 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 inFILES is the name from the <input type="file" name="">. Eachvalue in FILES is an UploadedFile.

See 管理文件 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 headersdepend 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.
    • SERVERPORT — The port of the server (as a string).With the exception of CONTENT_LENGTH and CONTENT_TYPE, as givenabove, any HTTP headers in the request are converted to META keys byconverting all characters to uppercase, replacing any hyphens withunderscores and adding an HTTP prefix to the name. So, for example, aheader called X-Bender would be mapped to the META keyHTTP_X_BENDER.

Note that runserver strips all headers with underscores in thename, so you won't see them in META. This prevents header-spoofingbased on ambiguity between underscores and dashes both being normalizing tounderscores in WSGI environment variables. It matches the behavior ofWeb servers like Nginx and Apache 2.4+.

HttpRequest.headers is a simpler way to access all HTTP-prefixedheaders, plus CONTENT_LENGTH and CONTENT_TYPE.

  • HttpRequest.headers
  • New in Django 2.2:

A case insensitive, dict-like object that provides access to allHTTP-prefixed headers (plus Content-Length and Content-Type) fromthe 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:

  1. >>> request.headers
  2. {'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6', ...}
  3.  
  4. >>> 'User-Agent' in request.headers
  5. True
  6. >>> 'user-agent' in request.headers
  7. True
  8.  
  9. >>> request.headers['User-Agent']
  10. Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
  11. >>> request.headers['user-agent']
  12. Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
  13.  
  14. >>> request.headers.get('User-Agent')
  15. Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
  16. >>> request.headers.get('user-agent')
  17. Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6)
  • HttpRequest.resolver_match
  • An instance of ResolverMatch representing theresolved URL. This attribute is only set after URL resolving took place,which means it's available in all views but not in middleware which areexecuted before URL resolving takes place (you can use it inprocess_view() though).

Attributes set by application code

Django doesn't set these attributes itself but makes use of them if set by yourapplication.

urlconf can be set to None to revert any changes made by previousmiddleware and return to using the ROOT_URLCONF.

Attributes set by middleware

Some of the middleware included in Django's contrib apps set attributes on therequest. If you don't see the attribute on a request, be sure the appropriatemiddleware class is listed in MIDDLEWARE.

  1. if request.user.is_authenticated:
  2.     ... # Do something for logged-in users.
  3. else:
  4.     ... # Do something for anonymous users.

方法

  • HttpRequest.get_host()[源代码]
  • Returns the originating host of the request using information from theHTTP_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 asdetailed in PEP 3333.

Example: "127.0.0.1:8000"

注解

The get_host() method fails when the host isbehind multiple proxies. One solution is to use middleware to rewritethe proxy headers, as in the following example:

  1. from django.utils.deprecation import MiddlewareMixin
  2.  
  3. class MultipleProxyMiddleware(MiddlewareMixin):
  4.     FORWARDED_FOR_FIELDS = [
  5.         'HTTP_X_FORWARDED_FOR',
  6.         'HTTP_X_FORWARDED_HOST',
  7.         'HTTP_X_FORWARDED_SERVER',
  8.     ]
  9.  
  10.     def process_request(self, request):
  11.         """
  12.         Rewrites the proxy headers so that only the most
  13.         recent proxy is used.
  14.         """
  15.         for field in self.FORWARDED_FOR_FIELDS:
  16.             if field in request.META:
  17.                 if ',' in request.META[field]:
  18.                     parts = request.META[field].split(',')
  19.                     request.META[field] = parts[-1].strip()

This middleware should be positioned before any other middleware thatrelies on the value of get_host() — for instance,CommonMiddleware orCsrfViewMiddleware.

  • HttpRequest.get_port()[源代码]

  • Returns the originating port of the request using information from theHTTP_X_FORWARDED_PORT (if USE_X_FORWARDED_PORT is enabled)and SERVER_PORT META variables, in that order.

  • HttpRequest.get_full_path()[源代码]

  • Returns the path, plus an appended query string, if applicable.

Example: "/music/bands/the_beatles/?print=true"

  • HttpRequest.get_full_path_info()[源代码]
  • New in Django 2.1:

Like get_full_path(), but uses path_info instead ofpath.

Example: "/minfo/music/bands/the_beatles/?print=true"

  • HttpRequest.buildabsolute_uri(_location=None)[源代码]
  • 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 inthis request. For example:

  1. >>> request.build_absolute_uri()
  2. 'https://example.com/music/bands/the_beatles/?print=true'
  3. >>> request.build_absolute_uri('/bands/')
  4. 'https://example.com/bands/'
  5. >>> request.build_absolute_uri('https://example2.com/bands/')
  6. 'https://example2.com/bands/'

注解

Mixing HTTP and HTTPS on the same site is discouraged, thereforebuild_absolute_uri() will always generate anabsolute URI with the same scheme the current request has. If you needto redirect users to HTTPS, it's best to let your Web server redirectall HTTP traffic to HTTPS.

  • HttpRequest.getsigned_cookie(_key, default=RAISE_ERROR, salt='', max_age=None)[源代码]
  • Returns a cookie value for a signed cookie, or raises adjango.core.signing.BadSignature exception if the signature isno longer valid. If you provide the default argument the exceptionwill be suppressed and that default value will be returned instead.

The optional salt argument can be used to provide extra protectionagainst brute force attacks on your secret key. If supplied, themax_age argument will be checked against the signed timestampattached to the cookie value to ensure the cookie is not older thanmax_age seconds.

例子:

  1. >>> request.get_signed_cookie('name')
  2. 'Tony'
  3. >>> request.get_signed_cookie('name', salt='name-salt')
  4. 'Tony' # assuming cookie was set using the same salt
  5. >>> request.get_signed_cookie('nonexistent-cookie')
  6. ...
  7. KeyError: 'nonexistent-cookie'
  8. >>> request.get_signed_cookie('nonexistent-cookie', False)
  9. False
  10. >>> request.get_signed_cookie('cookie-that-was-tampered-with')
  11. ...
  12. BadSignature: ...
  13. >>> request.get_signed_cookie('name', max_age=60)
  14. ...
  15. SignatureExpired: Signature age 1677.3839159 > 60 seconds
  16. >>> request.get_signed_cookie('name', False, max_age=60)
  17. False

See cryptographic signing for more information.

  • HttpRequest.is_secure()[源代码]

  • Returns True if the request is secure; that is, if it was made withHTTPS.

  • HttpRequest.is_ajax()[源代码]

  • Returns True if the request was made via an XMLHttpRequest, bychecking 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'llhave 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 areusing some form of caching like Django's cache middleware, you should decorate the view withvary_on_headers('X-Requested-With') so that the responses areproperly cached.

  • HttpRequest.read(size=None)[源代码]
  • HttpRequest.readline()[源代码]
  • HttpRequest.readlines()[源代码]
  • HttpRequest.iter()[源代码]
  • Methods implementing a file-like interface for reading from anHttpRequest instance. This makes it possible to consume an incomingrequest in a streaming fashion. A common use-case would be to process abig XML payload with an iterative parser without constructing a wholeXML tree in memory.

Given this standard interface, an HttpRequest instance can bepassed directly to an XML parser such asElementTree:

  1. import xml.etree.ElementTree as ET
  2. for element in ET.iterparse(request):
  3.     process(element)

QueryDict objects

  • class QueryDict[源代码]
  • In an HttpRequest object, the GET andPOST attributes are instances of django.http.QueryDict,a dictionary-like class customized to deal with multiple values for the samekey. This is necessary because some HTML form elements, notably<select multiple>, pass multiple values for the same key.

The QueryDicts at request.POST and request.GET will be immutablewhen accessed in a normal request/response cycle. To get a mutable version youneed to use QueryDict.copy().

方法

QueryDict implements all the standard dictionary methods because it'sa subclass of dictionary. Exceptions are outlined here:

  • QueryDict.init(query_string=None, mutable=False, encoding=None)[源代码]
  • Instantiates a QueryDict object based on query_string.
  1. >>> QueryDict('a=1&a=2&c=3')
  2. <QueryDict: {'a': ['1', '2'], 'c': ['3']}>

If query_string is not passed in, the resulting QueryDict will beempty (it will have no keys or values).

Most QueryDicts you encounter, and in particular those atrequest.POST and request.GET, will be immutable. If you areinstantiating one yourself, you can make it mutable by passingmutable=True to its init().

Strings for setting both keys and values will be converted from encodingto str. If encoding is not set, it defaults toDEFAULT_CHARSET.

  • classmethod QueryDict.fromkeys(iterable, value='', mutable=False, encoding=None)[源代码]
  • Creates a new QueryDict with keys from iterable and each valueequal to value. For example:
  1. >>> QueryDict.fromkeys(['a', 'a', 'b'], value='val')
  2. <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. Raisesdjango.utils.datastructures.MultiValueDictKeyError if the key does notexist. (This is a subclass of Python's standard KeyError, so you canstick to catching KeyError.)

  • QueryDict.setitem(key, value)[源代码]

  • Sets the given key to [value] (a list whose single element isvalue). Note that this, as other dictionary functions that have sideeffects, can only be called on a mutable QueryDict (such as one thatwas 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 adefault value if the key doesn't exist.

  • QueryDict.setdefault(key, default=None)[源代码]

  • 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 replacingthem. For example:
  1. >>> q = QueryDict('a=1', mutable=True)
  2. >>> q.update({'a': '2'})
  3. >>> q.getlist('a')
  4. ['1', '2']
  5. >>> q['a'] # returns the last
  6. '2'
  • QueryDict.items()
  • Like dict.items(), except this uses the same last-value logic asgetitem() and returns an iterator object instead of a view object.For example:
  1. >>> q = QueryDict('a=1&a=2&a=3')
  2. >>> list(q.items())
  3. [('a', '3')]
  • QueryDict.values()
  • Like dict.values(), except this uses the same last-value logic asgetitem() and returns an iterator instead of a view object. Forexample:
  1. >>> q = QueryDict('a=1&a=2&a=3')
  2. >>> list(q.values())
  3. ['3']

In addition, QueryDict has the following methods:

  • QueryDict.copy()[源代码]

  • Returns a copy of the object using copy.deepcopy(). This copy willbe 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 ifthe key doesn't exist and a default value wasn't provided. It's guaranteedto return a list unless the default value provided isn't a list.

  • QueryDict.setlist(key, list_)[源代码]

  • Sets the given key to list (unlike [setitem()]($b6ffb85eeff1d32c.md#django.http.QueryDict._setitem)).

  • QueryDict.appendlist(key, item)[源代码]

  • Appends an item to the internal list associated with key.

  • QueryDict.setlistdefault(key, default_list=None)[源代码]

  • Like setdefault(), except it takes a list of values instead of asingle value.

  • QueryDict.lists()

  • Like items(), except it includes all values, as a list, for eachmember of the dictionary. For example:
  1. >>> q = QueryDict('a=1&a=2&a=3')
  2. >>> q.lists()
  3. [('a', ['1', '2', '3'])]
  • QueryDict.pop(key)[源代码]
  • Returns a list of values for the given key and removes them from thedictionary. Raises KeyError if the key does not exist. For example:
  1. >>> q = QueryDict('a=1&a=2&a=3', mutable=True)
  2. >>> q.pop('a')
  3. ['1', '2', '3']
  • QueryDict.popitem()[源代码]
  • Removes an arbitrary member of the dictionary (since there's no conceptof ordering), and returns a two value tuple containing the key and a listof all values for the key. Raises KeyError when called on an emptydictionary. For example:
  1. >>> q = QueryDict('a=1&a=2&a=3', mutable=True)
  2. >>> q.popitem()
  3. ('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 oneelement of the list, using the same logic as QueryDict.getitem():
  1. >>> q = QueryDict('a=1&a=3&a=5')
  2. >>> q.dict()
  3. {'a': '5'}
  • QueryDict.urlencode(safe=None)[源代码]
  • Returns a string of the data in query string format. For example:
  1. >>> q = QueryDict('a=2&b=3&b=5')
  2. >>> q.urlencode()
  3. 'a=2&b=3&b=5'

Use the safe parameter to pass characters which don't require encoding.For example:

  1. >>> q = QueryDict(mutable=True)
  2. >>> q['next'] = '/a&b/'
  3. >>> q.urlencode(safe='/')
  4. 'next=/a%26b/'

HttpResponse objects

  • class HttpResponse[源代码]
  • In contrast to HttpRequest objects, which are created automatically byDjango, HttpResponse objects are your responsibility. Each view youwrite is responsible for instantiating, populating, and returning anHttpResponse.

The HttpResponse class lives in the django.http module.

用法

Passing strings

Typical usage is to pass the contents of the page, as a string or bytestring,to the HttpResponse constructor:

  1. >>> from django.http import HttpResponse
  2. >>> response = HttpResponse("Here's the text of the Web page.")
  3. >>> response = HttpResponse("Text only, please.", content_type="text/plain")
  4. >>> response = HttpResponse(b'Bytestrings are also accepted.')

But if you want to add content incrementally, you can use response as afile-like object:

  1. >>> response = HttpResponse()
  2. >>> response.write("<p>Here's the text of the Web page.</p>")
  3. >>> 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 astring, and discard it. Objects with a close() method such as files andgenerators are immediately closed.

If you need the response to be streamed from the iterator to the client, youmust use the StreamingHttpResponse class instead.

Setting header fields

To set or remove a header field in your response, treat it like a dictionary:

  1. >>> response = HttpResponse()
  2. >>> response['Age'] = 120
  3. >>> del response['Age']

Note that unlike a dictionary, del doesn't raise KeyError if the headerfield doesn't exist.

For setting the Cache-Control and Vary header fields, it is recommendedto use the patch_cache_control() andpatch_vary_headers() methods fromdjango.utils.cache, since these fields can have multiple, comma-separatedvalues. The "patch" methods ensure that other values, e.g. added by amiddleware, are not removed.

HTTP header fields cannot contain newlines. An attempt to set a header fieldcontaining 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, use thecontent_type argument and set the Content-Disposition header. For example,this is how you might return a Microsoft Excel spreadsheet:

  1. >>> response = HttpResponse(my_data, content_type='application/vnd.ms-excel')
  2. >>> response['Content-Disposition'] = 'attachment; filename="foo.xls"'

There's nothing Django-specific about the Content-Disposition header, butit's easy to forget the syntax, so we've included it here.

属性

  • 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 notgiven at HttpResponse instantiation time, it will be extracted fromcontent_type and if that is unsuccessful, theDEFAULT_CHARSET setting will be used.

  • HttpResponse.status_code

  • The HTTP status code for the response.

Unless reason_phrase is explicitly set, modifying the value ofstatus_code outside the constructor will also modify the value ofreason_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 ofstatus_code.

  • HttpResponse.streaming
  • This is always False.

This attribute exists so middleware can treat streaming responsesdifferently from regular responses.

  • HttpResponse.closed
  • True if the response has been closed.

方法

  • HttpResponse.init(content=b'', content_type=None, status=200, reason=None, charset=None)[源代码]
  • Instantiates an HttpResponse object with the given page content andcontent type.

content is most commonly an iterator, bytestring, or string. Othertypes will be converted to a bytestring by encoding their stringrepresentation. Iterators should return strings or bytestrings and thosewill be joined together to form the content of the response.

contenttype is the MIME type optionally completed by a character setencoding and is used to fill the HTTP Content-Type header. If notspecified, it is formed by the DEFAULT_CONTENT_TYPE andDEFAULT_CHARSET settings, by default: "_text/html; charset=utf-8".

status is the HTTP status code for the response.

reason is the HTTP response phrase. If not provided, a default phrasewill be used.

charset is the charset in which the response will be encoded. If notgiven it will be extracted from content_type, and if thatis unsuccessful, the DEFAULT_CHARSET setting will be used.

  • HttpResponse.setitem(header, value)

  • Sets the given header name to the given value. Both header andvalue should be strings.

  • HttpResponse.delitem(header)

  • Deletes the header with the given name. Fails silently if the headerdoesn't exist. Case-insensitive.

  • HttpResponse.getitem(header)

  • Returns the value for the given header name. Case-insensitive.

  • HttpResponse.hasheader(_header)

  • Returns True or False based on a case-insensitive check for aheader with the given name.

  • HttpResponse.setdefault(header, value)

  • Sets a header unless it has already been set.

  • HttpResponse.setcookie(_key, value='', max_age=None, expires=None, path='/', domain=None, secure=None, httponly=False, samesite=None)

  • Sets a cookie. The parameters are the same as in theMorsel cookie object in the Python standard library.

    • max_age should be a number of seconds, or None (default) ifthe 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 objectin UTC. If expires is a datetime object, the max_agewill 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 thedomains www.example.com, blog.example.com, etc. Otherwise, a cookie willonly be readable by the domain that set it.

    • Use httponly=True if you want to prevent client-sideJavaScript from having access to the cookie.

HttpOnly is a flag included in a Set-Cookie HTTP response header. It'spart of the RFC 6265 standard for cookies and can be a useful way tomitigate the risk of a client-side script accessing the protected cookiedata.

  • Use samesite='Strict' or samesite='Lax' to tell the browser notto send this cookie when performing a cross-origin request. SameSiteisn't supported by all browsers, so it's not a replacement for Django'sCSRF protection, but rather a defense in depth measure.

Changed in Django 2.1:The samesite argument was added.

警告

RFC 6265 states that user agents should support cookies of at least4096 bytes. For many browsers this is also the maximum size. Djangowill not raise an exception if there's an attempt to store a cookie ofmore than 4096 bytes, but many browsers will not set the cookiecorrectly.

  • HttpResponse.setsigned_cookie(_key, value, salt='', max_age=None, expires=None, path='/', domain=None, secure=None, httponly=False, samesite=None)

  • Like set_cookie(), butcryptographic signing the cookie before settingit. Use in conjunction with HttpRequest.get_signed_cookie().You can use the optional salt argument for added key strength, butyou will need to remember to pass it to the correspondingHttpRequest.get_signed_cookie() call.

  • HttpResponse.deletecookie(_key, path='/', domain=None)

  • Deletes the cookie with the given key. Fails silently if the key doesn'texist.

Due to the way cookies work, path and domain should be the samevalues you used in set_cookie() — otherwise the cookie may not bedeleted.

  • HttpResponse.close()

  • This method is called at the end of the request directly by the WSGIserver.

  • HttpResponse.write(content)[源代码]

  • This method makes an HttpResponse instance a file-like object.

  • HttpResponse.flush()

  • This method makes an HttpResponse instance a file-like object.

  • HttpResponse.tell()[源代码]

  • This method makes an HttpResponse instance a file-like object.

  • HttpResponse.getvalue()[源代码]

  • Returns the value of HttpResponse.content. This method makesan HttpResponse instance a stream-like object.

  • HttpResponse.readable()

  • Always False. This method makes an HttpResponse instance astream-like object.

  • HttpResponse.seekable()

  • Always False. This method makes an HttpResponse instance astream-like object.

  • HttpResponse.writable()[源代码]

  • Always True. This method makes an HttpResponse instance astream-like object.

  • HttpResponse.writelines(lines)[源代码]

  • Writes a list of lines to the response. Line separators are not added. Thismethod makes an HttpResponse instance a stream-like object.

HttpResponse subclasses

Django includes a number of HttpResponse subclasses that handle differenttypes of HTTP responses. Like HttpResponse, these subclasses live indjango.http.

  • class HttpResponseRedirect[源代码]

  • The first argument to the constructor is required — the path to redirectto. This can be a fully qualified URL(e.g. 'https://www.yahoo.com/search/&#39;), an absolute path with no domain(e.g. '/search/'), or even a relative path (e.g. 'search/'). In thatlast case, the client browser will reconstruct the full URL itselfaccording to the current path. See HttpResponse for other optionalconstructor arguments. Note that this returns an HTTP status code 302.

    • url
    • This read-only attribute represents the URL the response will redirectto (equivalent to the Location response header).

  • class HttpResponsePermanentRedirect[源代码]

  • Like HttpResponseRedirect, but it returns a permanent redirect(HTTP status code 301) instead of a "found" redirect (status code 302).

  • class HttpResponseNotModified[源代码]

  • The constructor doesn't take any arguments and no content should be addedto this response. Use this to designate that a page hasn't been modifiedsince the user's last request (status code 304).

  • class HttpResponseBadRequest[源代码]

  • Acts just like HttpResponse but uses a 400 status code.

  • class HttpResponseNotFound[源代码]

  • Acts just like HttpResponse but uses a 404 status code.

  • class HttpResponseForbidden[源代码]

  • Acts just like HttpResponse but uses a 403 status code.

  • class HttpResponseNotAllowed[源代码]

  • Like HttpResponse, but uses a 405 status code. The first argumentto the constructor is required: a list of permitted methods (e.g.['GET', 'POST']).

  • class HttpResponseGone[源代码]

  • Acts just like HttpResponse but uses a 410 status code.

  • class HttpResponseServerError[源代码]

  • Acts just like HttpResponse but uses a 500 status code.

注解

If a custom subclass of HttpResponse implements a rendermethod, Django will treat it as emulating aSimpleTemplateResponse, and therender method must itself return a valid response object.

JsonResponse objects

  • class JsonResponse(data, encoder=DjangoJSONEncoder, safe=True, json_dumps_params=None, **kwargs)[源代码]
  • An HttpResponse subclass that helps to create a JSON-encodedresponse. It inherits most behavior from its superclass with a coupledifferences:

Its default Content-Type header is set to application/json.

The first parameter, data, should be a dict instance. If thesafe parameter is set to False (see below) it can be anyJSON-serializable object.

The encoder, which defaults todjango.core.serializers.json.DjangoJSONEncoder, will be used toserialize the data. See JSON serialization for more details about this serializer.

The safe boolean parameter defaults to True. If it's set toFalse, any object can be passed for serialization (otherwise onlydict instances are allowed). If safe is True and a non-dictobject is passed as the first argument, a TypeError will be raised.

The json_dumps_params parameter is a dictionary of keyword argumentsto pass to the json.dumps() call used to generate the response.

用法

Typical usage could look like:

  1. >>> from django.http import JsonResponse
  2. >>> response = JsonResponse({'foo': 'bar'})
  3. >>> response.content
  4. b'{"foo": "bar"}'

Serializing non-dictionary objects

In order to serialize objects other than dict you must set the safeparameter to False:

  1. >>> response = JsonResponse([1, 2, 3], safe=False)

Without passing safe=False, a TypeError will be raised.

警告

Before the 5th edition of ECMAScriptit was possible to poison the JavaScript Array constructor. For thisreason, Django does not allow passing non-dict objects to theJsonResponse constructor by default. However, mostmodern 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 encoderparameter to the constructor method:

  1. >>> response = JsonResponse(data, encoder=MyJSONEncoder)

StreamingHttpResponse objects

性能考虑因素

Django is designed for short-lived requests. Streaming responses will tiea worker process for the entire duration of the response. This may resultin poor performance.

Generally speaking, you should perform expensive tasks outside of therequest-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:

  • It should be given an iterator that yields strings as content.
  • You cannot access its content, except by iterating the response objectitself. This should only occur when the response is returned to the client.
  • It has no content attribute. Instead, it has astreaming_content attribute.
  • You cannot use the file-like object tell() or write() methods.Doing so will raise an exception.StreamingHttpResponse should only be used in situations where it isabsolutely required that the whole content isn't iterated before transferringthe data to the client. Because the content can't be accessed, manymiddleware can't function normally. For example the ETag andContent-Length headers can't be generated for streaming responses.

属性

  • StreamingHttpResponse.streaming_content

  • An iterator of the response content, bytestring encoded according toHttpResponse.charset.

  • StreamingHttpResponse.status_code

  • The HTTP status code for the response.

Unless reason_phrase is explicitly set, modifying the value ofstatus_code outside the constructor will also modify the value ofreason_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 ofstatus_code.

  • StreamingHttpResponse.streaming
  • This is always True.

FileResponse objects

If as_attachment=True, the Content-Disposition header is set, whichasks 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'tappropriate, provide a custom file name using the filename parameter.Note that if you pass a file-like object like io.BytesIO, it's yourtask to seek() it before passing it to FileResponse.

The Content-Length, Content-Type, and Content-Dispositionheaders are automatically set when they can be guessed from contents ofopen_file.

New in Django 2.1:The as_attachment and filename keywords argument were added.Also, FileResponse sets the Content headers if it can guessthem.

FileResponse accepts any file-like object with binary content, for examplea file open in binary mode like so:

  1. >>> from django.http import FileResponse
  2. >>> response = FileResponse(open('myfile.png', 'rb'))

The file will be closed automatically, so don't open it with a context manager.

方法

  • FileResponse.setheaders(_open_file)[源代码]
  • New in Django 2.1:

This method is automatically called during the response initialization andset various headers (Content-Length, Content-Type, andContent-Disposition) depending on open_file.