`http.server` — HTTP servers¶

This module defines classes for implementing HTTP servers.

Warning

http.server is not recommended for production. It only implements basic security checks.

This module does not work or is not available on WebAssembly. See WebAssembly platforms for more information.

One class, HTTPServer, is a socketserver.TCPServer subclass. It creates and listens at the HTTP socket, dispatching the requests to a handler. Code to create and run the server looks like this:

def run(server_class=HTTPServer, handler_class=BaseHTTPRequestHandler):
    server_address = ('', 8000)
    httpd = server_class(server_address, handler_class)
    httpd.serve_forever()

class http.server.HTTPServer(server_address, RequestHandlerClass)¶

This class builds on the TCPServer class by storing the server address as instance variables named server_name and server_port. The server is accessible by the handler, typically through the handler’s server instance variable.

server_name¶: The HTTP server’s fully qualified domain name.

server_port¶: The HTTP server’s port number obtained from server_address.

class http.server.ThreadingHTTPServer(server_address, RequestHandlerClass)¶: This class is identical to HTTPServer but uses threads to handle requests by using the ThreadingMixIn. This is useful to handle web browsers pre-opening sockets, on which HTTPServer would wait indefinitely.

Added in version 3.7.

class http.server.HTTPSServer(server_address, RequestHandlerClass, bind_and_activate=True, *, certfile, keyfile=None, password=None, alpn_protocols=None)¶

Subclass of HTTPServer with a wrapped socket using the ssl module. If the ssl module is not available, instantiating a HTTPSServer object fails with a RuntimeError.

The certfile argument is the path to the SSL certificate chain file, and the keyfile is the path to the file containing the private key.

A password can be specified for files protected and wrapped with PKCS#8, but beware that this could possibly expose hardcoded passwords in clear.

See also

See ssl.SSLContext.load_cert_chain() for additional information on the accepted values for certfile, keyfile and password.

When specified, the alpn_protocols argument must be a sequence of strings specifying the “Application-Layer Protocol Negotiation” (ALPN) protocols supported by the server. ALPN allows the server and the client to negotiate the application protocol during the TLS handshake.

By default, it is set to ["http/1.1"], meaning the server supports HTTP/1.1.

Added in version 3.14.

class http.server.ThreadingHTTPSServer(server_address, RequestHandlerClass, bind_and_activate=True, *, certfile, keyfile=None, password=None, alpn_protocols=None)¶: This class is identical to HTTPSServer but uses threads to handle requests by inheriting from ThreadingMixIn. This is analogous to ThreadingHTTPServer only using HTTPSServer.

Added in version 3.14.

The HTTPServer, ThreadingHTTPServer, HTTPSServer and ThreadingHTTPSServer must be given a RequestHandlerClass on instantiation, of which this module provides three different variants:

class http.server.BaseHTTPRequestHandler(request, client_address, server)¶

This class is used to handle the HTTP requests that arrive at the server. By itself, it cannot respond to any actual HTTP requests; it must be subclassed to handle each request method (for example, 'GET' or 'POST'). BaseHTTPRequestHandler provides a number of class and instance variables, and methods for use by subclasses.

The handler will parse the request and the headers, then call a method specific to the request type. The method name is constructed from the request. For example, for the request method SPAM, the do_SPAM() method will be called with no arguments. All of the relevant information is stored in instance variables of the handler. Subclasses should not need to override or extend the __init__() method.

BaseHTTPRequestHandler has the following instance variables:

client_address¶: Contains a tuple of the form (host, port) referring to the client’s address.

server¶: Contains the server instance.

close_connection¶: Boolean that should be set before handle_one_request() returns, indicating if another request may be expected, or if the connection should be shut down.

requestline¶: Contains the string representation of the HTTP request line. The terminating CRLF is stripped. This attribute should be set by handle_one_request(). If no valid request line was processed, it should be set to the empty string.

command¶: Contains the command (request type). For example, 'GET'.

path¶: Contains the request path. If the query component of the URL is present, then path includes the query. Using the terminology of RFC 3986, path here includes hier-part and the query.

request_version¶: Contains the version string from the request. For example, 'HTTP/1.0'.

headers¶: Holds an instance of the class specified by the MessageClass class variable. This instance parses and manages the headers in the HTTP request. The parse_headers() function from http.client is used to parse the headers and it requires that the HTTP request provide a valid RFC 5322 style header.

rfile¶: An io.BufferedIOBase input stream, ready to read from the start of the optional input data.

wfile¶: Contains the output stream for writing a response back to the client. Proper adherence to the HTTP protocol must be used when writing to this stream in order to achieve successful interoperation with HTTP clients.

Changed in version 3.6: This is an io.BufferedIOBase stream.

BaseHTTPRequestHandler has the following attributes:

server_version¶: Specifies the server software version. You may want to override this. The format is multiple whitespace-separated strings, where each string is of the form name[/version]. For example, 'BaseHTTP/0.2'.

sys_version¶: Contains the Python system version, in a form usable by the version_string method and the server_version class variable. For example, 'Python/1.4'.

error_message_format¶: Specifies a format string that should be used by send_error() method for building an error response to the client. The string is filled by default with variables from responses based on the status code passed to send_error().

error_content_type¶: Specifies the Content-Type HTTP header of error responses sent to the client. The default value is 'text/html'.

protocol_version¶: Specifies the HTTP version to which the server is conformant. It is sent in responses to let the client know the server’s communication capabilities for future requests. If set to 'HTTP/1.1', the server will permit HTTP persistent connections; however, your server must then include an accurate Content-Length header (using send_header()) in all of its responses to clients. For backwards compatibility, the setting defaults to 'HTTP/1.0'.

MessageClass¶: Specifies an email.message.Message-like class to parse HTTP headers. Typically, this is not overridden, and it defaults to http.client.HTTPMessage.

responses¶: This attribute contains a mapping of error code integers to two-element tuples containing a short and long message. For example, {code: (shortmessage, longmessage)}. The shortmessage is usually used as the message key in an error response, and longmessage as the explain key. It is used by send_response_only() and send_error() methods.

A BaseHTTPRequestHandler instance has the following methods:

handle()¶: Calls handle_one_request() once (or, if persistent connections are enabled, multiple times) to handle incoming HTTP requests. You should never need to override it; instead, implement appropriate do_*() methods.

handle_one_request()¶: This method will parse and dispatch the request to the appropriate do_*() method. You should never need to override it.

handle_expect_100()¶: When an HTTP/1.1 conformant server receives an Expect: 100-continue request header it responds with a 100 Continue followed by 200 OK headers. This method can be overridden to raise an error if the server does not want the client to continue. For example, the server can choose to send 417 Expectation Failed as a response header and return False.

Added in version 3.2.

send_error(code, message=None, explain=None)¶: Sends and logs a complete error reply to the client. The numeric code specifies the HTTP error code, with message as an optional, short, human readable description of the error. The explain argument can be used to provide more detailed information about the error; it will be formatted using the error_message_format attribute and emitted, after a complete set of headers, as the response body. The responses attribute holds the default values for message and explain that will be used if no value is provided; for unknown codes the default value for both is the string ???. The body will be empty if the method is HEAD or the response code is one of the following: 1xx, 204 No Content, 205 Reset Content, 304 Not Modified.

Changed in version 3.4: The error response includes a Content-Length header. Added the explain argument.

send_response(code, message=None)¶: Adds a response header to the headers buffer and logs the accepted request. The HTTP response line is written to the internal buffer, followed by Server and Date headers. The values for these two headers are picked up from the version_string() and date_time_string() methods, respectively. If the server does not intend to send any other headers using the send_header() method, then send_response() should be followed by an end_headers() call.

Changed in version 3.3: Headers are stored to an internal buffer and end_headers() needs to be called explicitly.

send_header(keyword, value)¶

Adds the HTTP header to an internal buffer which will be written to the output stream when either end_headers() or flush_headers() is invoked. keyword should specify the header keyword, with value specifying its value. Note that, after the send_header calls are done, end_headers() MUST BE called in order to complete the operation.

This method does not reject input containing CRLF sequences.

Changed in version 3.2: Headers are stored in an internal buffer.

send_response_only(code, message=None)¶

Sends the response header only, used for the purposes when 100 Continue response is sent by the server to the client. The headers are not buffered and sent directly the output stream. If the message is not specified, the HTTP message corresponding the response code is sent.

This method does not reject message containing CRLF sequences.

http.server — HTTP servers¶

`http.server` — HTTP servers¶