http.client — HTTP protocol client

Código-fonte: Lib/http/client.py

---

This module defines classes that implement the client side of the HTTP and HTTPS protocols. It is normally not used directly — the module urllib.request uses it to handle URLs that use HTTP and HTTPS.

Ver também

The Requests package is recommended for a higher-level HTTP client interface.

Nota

Suporte HTTPS está disponível somente se Python foi compilado com suporte SSL (através do módulo ssl).

Availability: not WASI.

Este módulo não funciona ou não está disponível em WebAssembly. Veja Plataformas WebAssembly para mais informações.

O módulo fornece as seguintes classes:

class http.client.HTTPConnection(host, port=None, [timeout, ]source_address=None, blocksize=8192)

An HTTPConnection instance represents one transaction with an HTTP server. It should be instantiated by passing it a host and optional port number. If no port number is passed, the port is extracted from the host string if it has the form host:port, else the default HTTP port (80) is used. If the optional timeout parameter is given, blocking operations (like connection attempts) will timeout after that many seconds (if it is not given, the global default timeout setting is used). The optional source_address parameter may be a tuple of a (host, port) to use as the source address the HTTP connection is made from. The optional blocksize parameter sets the buffer size in bytes for sending a file-like message body.

Por exemplo, todas as seguintes chamadas criam instâncias que conectam ao servidor com o mesmo host e porta:

>>> h1 = http.client.HTTPConnection('www.python.org')
>>> h2 = http.client.HTTPConnection('www.python.org:80')
>>> h3 = http.client.HTTPConnection('www.python.org', 80)
>>> h4 = http.client.HTTPConnection('www.python.org', 80, timeout=10)

Alterado na versão 3.2: source_address foi adicionado.

Alterado na versão 3.4: The strict parameter was removed. HTTP 0.9-style “Simple Responses” are no longer supported.

Alterado na versão 3.7: O argumento blocksize foi adicionado.

class http.client.HTTPSConnection(host, port=None, *, [timeout, ]source_address=None, context=None, blocksize=8192)

Uma subclasse de HTTPConnection que utiliza SSL para comunicação com servidores seguros. A porta padrão é 443. Se context for especificado, ele deve ser uma instância de ssl.SSLContext descrevendo as várias opções do SSL.

Por favor leia Considerações de segurança para mais informações sobre as melhores práticas.

Alterado na versão 3.2: source_address, context e check_hostname foram adicionados.

Alterado na versão 3.2: This class now supports HTTPS virtual hosts if possible (that is, if ssl.HAS_SNI is true).

Alterado na versão 3.4: O argumento strict foi removido. “Respostas Simples” HTTP com o estilo 0.9 não são mais suportadas.

Alterado na versão 3.4.3: This class now performs all the necessary certificate and hostname checks by default. To revert to the previous, unverified, behavior ssl._create_unverified_context() can be passed to the context parameter.

Alterado na versão 3.8: Esta classe agora habilita TLS 1.3 ssl.SSLContext.post_handshake_auth para o padrão context ou quanto cert_file é fornecido com um context personalizado.

Alterado na versão 3.10: This class now sends an ALPN extension with protocol indicator http/1.1 when no context is given. Custom context should set ALPN protocols with set_alpn_protocols().

Alterado na versão 3.12: The deprecated key_file, cert_file and check_hostname parameters have been removed.

class http.client.HTTPResponse(sock, debuglevel=0, method=None, url=None)

Classe em que instâncias são retornadas mediante de conexão bem-sucedida. Não é instanciável diretamente pelo usuário.

Alterado na versão 3.4: O argumento strict foi removido. “Respostas Simples” HTTP com o estilo 0.9 não são mais suportadas.

Este módulo fornece a seguinte função:

http.client.parse_headers(fp)

Parse the headers from a file pointer fp representing a HTTP request/response. The file has to be a BufferedIOBase reader (i.e. not text) and must provide a valid RFC 2822 style header.

Esta função retorna uma instância de http.client.HTTPMessage que armazena os campos do cabeçalho, mas não o payload (o mesmo que HTTPResponse.msg e http.server.BaseHTTPRequestHandler.headers). Depois de retornar, o ponteiro de arquivo fp está pronto para ler o corpo da requisição HTTP.

Nota

parse_headers() não analisa a linha inicial de uma mensagem HTTP; ele apenas analisa as linhas de Name: value. O arquivo deve estar pronto para ler essas linhas de campo, então a primeira linha já deve ter sido consumida antes de chamar a função.

As seguintes exceções são levantadas conforme apropriado:

exception http.client.HTTPException

A classe base das outras exceções neste módulo. É uma subclasse de Exception.

exception http.client.NotConnected

Uma subclasse de HTTPException.

exception http.client.InvalidURL

Uma subclasse de HTTPException, levantada se uma porta é fornecida e esta é não-numérica ou vazia.

exception http.client.UnknownProtocol

Uma subclasse de HTTPException.

exception http.client.UnknownTransferEncoding

Uma subclasse de HTTPException.

exception http.client.UnimplementedFileMode

Uma subclasse de HTTPException.

exception http.client.IncompleteRead

Uma subclasse de HTTPException.

exception http.client.ImproperConnectionState

Uma subclasse de HTTPException.

exception http.client.CannotSendRequest

Uma subclasse de ImproperConnectionState.

exception http.client.CannotSendHeader

Uma subclasse de ImproperConnectionState.

exception http.client.ResponseNotReady

Uma subclasse de ImproperConnectionState.

exception http.client.BadStatusLine

Uma subclasse de HTTPException. Levantada se um servidor responde com um código de status HTTP que não é entendido.

exception http.client.LineTooLong

Uma subclasse de HTTPException. Levantada se uma linha excessivamente longa é recebida, do servidor, no protocolo HTTP.

exception http.client.RemoteDisconnected

Uma subclasse de ConnectionResetError e BadStatusLine. Levantada por HTTPConnection.getresponse() quando a tentativa de ler a resposta resulta na não leitura dos dados pela conexão, indicando que o fim remoto fechou a conexão.

Adicionado na versão 3.5: Anteriormente, a exceção BadStatusLine('') foi levantada.

As constantes definidas neste módulo são:

http.client.HTTP_PORT

A porta padrão para o protocolo HTTP (sempre 80).

http.client.HTTPS_PORT

A porta padrão para o protocolo HTTPS (sempre 443).

http.client.responses

Este dicionário mapeia os códigos de status HTTP 1.1 para os nomes em W3C.

Exemplo: http.client.responses[http.client.NOT_FOUND] é 'Not Found'.

Ver códigos de status HTTP para uma lista de códigos de status HTTP que estão disponíveis neste módulo como constantes.

Objetos de HTTPConnection

Instâncias HTTPConnection contêm os seguintes métodos:

HTTPConnection.request(method, url, body=None, headers={}, *, encode_chunked=False)

This will send a request to the server using the HTTP request method method and the request URI url. The provided url must be an absolute path to conform with RFC 2616 §5.1.2 (unless connecting to an HTTP proxy server or using the OPTIONS or CONNECT methods).

Se body é especificado, os dados especificados são mandados depois que os cabeçalhos estão prontos. Pode ser um str, um objeto byte ou similar, um objeto arquivo aberto, ou um iterável de bytes. Se body é uma string, ele é codificado como ISO-8859-1, o padrão para HTTP. Se é um objeto do tipo byte, os bytes são enviados como estão. Se é um objeto arquivo, o conteúdo do arquivo é enviado; este objeto arquivo deve suportar pelo menos o método read(). Se o objeto arquivo é uma instância de io.TextIOBase, os dados retornados pelo método read() será codificado como ISO-8859-1, de outra forma os dados retornados por read() são enviados como estão. Se body é um iterável, os elementos do iterável são enviados até os mesmo se esgotar.

The headers argument should be a mapping of extra HTTP headers to send with the request. A Host header must be provided to conform with RFC 2616 §5.1.2 (unless connecting to an HTTP proxy server or using the OPTIONS or CONNECT methods).

If headers contains neither Content-Length nor Transfer-Encoding, but there is a request body, one of those header fields will be added automatically. If body is None, the Content-Length header is set to 0 for methods that expect a body (PUT, POST, and PATCH). If body is a string or a bytes-like object that is not also a file, the Content-Length header is set to its length. Any other type of body (files and iterables in general) will be chunk-encoded, and the Transfer-Encoding header will automatically be set instead of Content-Length.

The encode_chunked argument is only relevant if Transfer-Encoding is specified in headers. If encode_chunked is False, the HTTPConnection object assumes that all encoding is handled by the calling code. If it is True, the body will be chunk-encoded.

For example, to perform a GET request to https://docs.python.org/3/:

>>> import http.client
>>> host = "docs.python.org"
>>> conn = http.client.HTTPSConnection(host)
>>> conn.request("GET", "/3/", headers={"Host": host})
>>> response = conn.getresponse()
>>> print(response.status, response.reason)
200 OK

Nota

Chunked transfer encoding has been added to the HTTP protocol version 1.1. Unless the HTTP server is known to handle HTTP 1.1, the caller must either specify the Content-Length, or must pass a str or bytes-like object that is not also a file as the body representation.

Alterado na versão 3.2: body pode agora ser um iterável.

Alterado na versão 3.6: If neither Content-Length nor Transfer-Encoding are set in headers, file and iterable body objects are now chunk-encoded. The encode_chunked argument was added. No attempt is made to determine the Content-Length for file objects.

HTTPConnection.getresponse()

Should be called after a request is sent to get the response from the server. Returns an HTTPResponse instance.

Nota

Note that you must have read the whole response before you can send a new request to the server.

Alterado na versão 3.5: Se uma ConnectionError ou subclasse for levantada, o objeto HTTPConnection estará pronto para se reconectar quando uma nova solicitação for enviada.

HTTPConnection.set_debuglevel(level)

Set the debugging level. The default debug level is 0, meaning no debugging output is printed. Any value greater than 0 will cause all currently defined debug output to be printed to stdout. The debuglevel is passed to any new HTTPResponse objects that are created.

Adicionado na versão 3.1.

HTTPConnection.set_tunnel(host, port=None, headers=None)

Set the host and the port for HTTP Connect Tunnelling. This allows running the connection through a proxy server.

The host and port arguments specify the endpoint of the tunneled connection (i.e. the address included in the CONNECT request, not the address of the proxy server).

The headers argument should be a mapping of extra HTTP headers to send with the CONNECT request.

As HTTP/1.1 is used for HTTP CONNECT tunnelling request, as per the RFC, a HTTP Host: header must be provided, matching the authority-form of the request target provided as the destination for the CONNECT request. If a HTTP Host: header is not provided via the headers argument, one is generated and transmitted automatically.

For example, to tunnel through a HTTPS proxy server running locally on port 8080, we would pass the address of the proxy to the HTTPSConnection constructor, and the address of the host that we eventually want to reach to the set_tunnel() method:

>>> import http.client
>>> conn = http.client.HTTPSConnection("localhost", 8080)
>>> conn.set_tunnel("www.python.org")
>>> conn.request("HEAD","/index.html")

Adicionado na versão 3.2.

Alterado na versão 3.12: HTTP CONNECT tunnelling requests use protocol HTTP/1.1, upgraded from protocol HTTP/1.0. Host: HTTP headers are mandatory for HTTP/1.1, so one will be automatically generated and transmitted if not provided in the headers argument.

HTTPConnection.get_proxy_response_headers()

Returns a dictionary with the headers of the response received from the proxy server to the CONNECT request.

If the CONNECT request was not sent, the method returns None.

Adicionado na versão 3.12.

HTTPConnection.connect()

Connect to the server specified when the object was created. By default, this is called automatically when making a request if the client does not already have a connection.

Levanta um evento de auditoria http.client.connect com os argumentos self, host, port.

HTTPConnection.close()

Close the connection to the server.

HTTPConnection.blocksize

Buffer size in bytes for sending a file-like message body.

Adicionado na versão 3.7.

As an alternative to using the request() method described above, you can also send your request step by step, by using the four functions below.

HTTPConnection.putrequest(method, url, skip_host=False, skip_accept_encoding=False)

This should be the first call after the connection to the server has been made. It sends a line to the server consisting of the method string, the url string, and the HTTP version (HTTP/1.1). To disable automatic sending of Host: or Accept-Encoding: headers (for example to accept additional content encodings), specify skip_host or skip_accept_encoding with non-False values.

HTTPConnection.putheader(header, argument[, ...])

Send an RFC 822-style header to the server. It sends a line to the server consisting of the header, a colon and a space, and the first argument. If more arguments are given, continuation lines are sent, each consisting of a tab and an argument.

HTTPConnection.endheaders(message_body=None, *, encode_chunked=False)

Send a blank line to the server, signalling the end of the headers. The optional message_body argument can be used to pass a message body associated with the request.

If encode_chunked is True, the result of each iteration of message_body will be chunk-encoded as specified in RFC 7230, Section 3.3.1. How the data is encoded is dependent on the type of message_body. If message_body implements the buffer interface the encoding will result in a single chunk. If message_body is a collections.abc.Iterable, each iteration of message_body will result in a chunk. If message_body is a file object, each call to .read() will result in a chunk. The method automatically signals the end of the chunk-encoded data immediately after message_body.

Nota

Due to the chunked encoding specification, empty chunks yielded by an iterator body will be ignored by the chunk-encoder. This is to avoid premature termination of the read of the request by the target server due to malformed encoding.

Alterado na versão 3.6: Added chunked encoding support and the encode_chunked parameter.

HTTPConnection.send(data)

Send data to the server. This should be used directly only after the endheaders() method has been called and before getresponse() is called.

Levanta um evento de auditoria http.client.send com os argumentos self, data.

Objetos HTTPResponse

An HTTPResponse instance wraps the HTTP response from the server. It provides access to the request headers and the entity body. The response is an iterable object and can be used in a with statement.

Alterado na versão 3.5: The io.BufferedIOBase interface is now implemented and all of its reader operations are supported.

HTTPResponse.read([amt])

Reads and returns the response body, or up to the next amt bytes.

HTTPResponse.readinto(b)

Reads up to the next len(b) bytes of the response body into the buffer b. Returns the number of bytes read.

Adicionado na versão 3.3.

HTTPResponse.getheader(name, default=None)

Return the value of the header name, or default if there is no header matching name. If there is more than one header with the name name, return all of the values joined by ‘, ‘. If default is any iterable other than a single string, its elements are similarly returned joined by commas.

HTTPResponse.getheaders()

Return a list of (header, value) tuples.

HTTPResponse.fileno()

Return the fileno of the underlying socket.

HTTPResponse.msg

A http.client.HTTPMessage instance containing the response headers. http.client.HTTPMessage is a subclass of email.message.Message.

HTTPResponse.version

HTTP protocol version used by server. 10 for HTTP/1.0, 11 for HTTP/1.1.

HTTPResponse.url

URL of the resource retrieved, commonly used to determine if a redirect was followed.

HTTPResponse.headers

Headers of the response in the form of an email.message.EmailMessage instance.

HTTPResponse.status

Status code returned by server.

HTTPResponse.reason

Reason phrase returned by server.

HTTPResponse.debuglevel

A debugging hook. If debuglevel is greater than zero, messages will be printed to stdout as the response is read and parsed.

HTTPResponse.closed

Is True if the stream is closed.

HTTPResponse.geturl()

Obsoleto desde a versão 3.9: Deprecated in favor of url.

HTTPResponse.info()

Obsoleto desde a versão 3.9: Deprecated in favor of headers.

HTTPResponse.getcode()

Obsoleto desde a versão 3.9: Deprecated in favor of status.

Exemplos

Here is an example session that uses the GET method:

>>> import http.client
>>> conn = http.client.HTTPSConnection("www.python.org")
>>> conn.request("GET", "/")
>>> r1 = conn.getresponse()
>>> print(r1.status, r1.reason)
200 OK
>>> data1 = r1.read()  # This will return entire content.
>>> # The following example demonstrates reading data in chunks.
>>> conn.request("GET", "/")
>>> r1 = conn.getresponse()
>>> while chunk := r1.read(200):
...     print(repr(chunk))
b'<!doctype html>\n<!--[if"...
...
>>> # Example of an invalid request
>>> conn = http.client.HTTPSConnection("docs.python.org")
>>> conn.request("GET", "/parrot.spam")
>>> r2 = conn.getresponse()
>>> print(r2.status, r2.reason)
404 Not Found
>>> data2 = r2.read()
>>> conn.close()

Here is an example session that uses the HEAD method. Note that the HEAD method never returns any data.

>>> import http.client
>>> conn = http.client.HTTPSConnection("www.python.org")
>>> conn.request("HEAD", "/")
>>> res = conn.getresponse()
>>> print(res.status, res.reason)
200 OK
>>> data = res.read()
>>> print(len(data))
0
>>> data == b''
True

Here is an example session that uses the POST method:

>>> import http.client, urllib.parse
>>> params = urllib.parse.urlencode({'@number': 12524, '@type': 'issue', '@action': 'show'})
>>> headers = {"Content-type": "application/x-www-form-urlencoded",
...            "Accept": "text/plain"}
>>> conn = http.client.HTTPConnection("bugs.python.org")
>>> conn.request("POST", "", params, headers)
>>> response = conn.getresponse()
>>> print(response.status, response.reason)
302 Found
>>> data = response.read()
>>> data
b'Redirecting to <a href="https://bugs.python.org/issue12524">https://bugs.python.org/issue12524</a>'
>>> conn.close()

Client side HTTP PUT requests are very similar to POST requests. The difference lies only on the server side where HTTP servers will allow resources to be created via PUT requests. It should be noted that custom HTTP methods are also handled in urllib.request.Request by setting the appropriate method attribute. Here is an example session that uses the PUT method:

>>> # This creates an HTTP request
>>> # with the content of BODY as the enclosed representation
>>> # for the resource http://localhost:8080/file
...
>>> import http.client
>>> BODY = "***filecontents***"
>>> conn = http.client.HTTPConnection("localhost", 8080)
>>> conn.request("PUT", "/file", BODY)
>>> response = conn.getresponse()
>>> print(response.status, response.reason)
200, OK

HTTPMessage Objects

class http.client.HTTPMessage(email.message.Message)

An http.client.HTTPMessage instance holds the headers from an HTTP response. It is implemented using the email.message.Message class.