Edit File: basehttpserver.txt
:mod:`BaseHTTPServer` --- Basic HTTP server =========================================== .. module:: BaseHTTPServer :synopsis: Basic HTTP server (base class for SimpleHTTPServer and CGIHTTPServer). .. note:: The :mod:`BaseHTTPServer` module has been merged into :mod:`http.server` in Python 3.0. The :term:`2to3` tool will automatically adapt imports when converting your sources to 3.0. .. index:: pair: WWW; server pair: HTTP; protocol single: URL single: httpd module: SimpleHTTPServer module: CGIHTTPServer This module defines two classes for implementing HTTP servers (Web servers). Usually, this module isn't used directly, but is used as a basis for building functioning Web servers. See the :mod:`SimpleHTTPServer` and :mod:`CGIHTTPServer` modules. The first class, :class:`HTTPServer`, is a :class:`SocketServer.TCPServer` subclass, and therefore implements the :class:`SocketServer.BaseServer` interface. 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=BaseHTTPServer.HTTPServer, handler_class=BaseHTTPServer.BaseHTTPRequestHandler): server_address = ('', 8000) httpd = server_class(server_address, handler_class) httpd.serve_forever() .. class:: HTTPServer(server_address, RequestHandlerClass) This class builds on the :class:`TCPServer` class by storing the server address as instance variables named :attr:`server_name` and :attr:`server_port`. The server is accessible by the handler, typically through the handler's :attr:`server` instance variable. .. class:: 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 (e.g. GET or POST). :class:`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 :meth:`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 :meth:`__init__` method. :class:`BaseHTTPRequestHandler` has the following instance variables: .. attribute:: client_address Contains a tuple of the form ``(host, port)`` referring to the client's address. .. attribute:: server Contains the server instance. .. attribute:: command Contains the command (request type). For example, ``'GET'``. .. attribute:: path Contains the request path. .. attribute:: request_version Contains the version string from the request. For example, ``'HTTP/1.0'``. .. attribute:: headers Holds an instance of the class specified by the :attr:`MessageClass` class variable. This instance parses and manages the headers in the HTTP request. .. attribute:: rfile Contains an input stream, positioned at the start of the optional input data. .. attribute:: 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. :class:`BaseHTTPRequestHandler` has the following class variables: .. attribute:: 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'``. .. attribute:: sys_version Contains the Python system version, in a form usable by the :attr:`version_string` method and the :attr:`server_version` class variable. For example, ``'Python/1.4'``. .. attribute:: error_message_format Specifies a format string for building an error response to the client. It uses parenthesized, keyed format specifiers, so the format operand must be a dictionary. The *code* key should be an integer, specifying the numeric HTTP error code value. *message* should be a string containing a (detailed) error message of what occurred, and *explain* should be an explanation of the error code number. Default *message* and *explain* values can found in the *responses* class variable. .. attribute:: error_content_type Specifies the Content-Type HTTP header of error responses sent to the client. The default value is ``'text/html'``. .. versionadded:: 2.6 Previously, the content type was always ``'text/html'``. .. attribute:: protocol_version This specifies the HTTP protocol version used in responses. 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 :meth:`send_header`) in all of its responses to clients. For backwards compatibility, the setting defaults to ``'HTTP/1.0'``. .. attribute:: MessageClass .. index:: single: Message (in module mimetools) Specifies a :class:`rfc822.Message`\ -like class to parse HTTP headers. Typically, this is not overridden, and it defaults to :class:`mimetools.Message`. .. attribute:: responses This variable 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 (see the :attr:`error_message_format` class variable). A :class:`BaseHTTPRequestHandler` instance has the following methods: .. method:: handle() Calls :meth:`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 :meth:`do_\*` methods. .. method:: handle_one_request() This method will parse and dispatch the request to the appropriate :meth:`do_\*` method. You should never need to override it. .. method:: send_error(code[, message]) Sends and logs a complete error reply to the client. The numeric *code* specifies the HTTP error code, with *message* as optional, more specific text. A complete set of headers is sent, followed by text composed using the :attr:`error_message_format` class variable. .. method:: send_response(code[, message]) Sends a response header and logs the accepted request. The HTTP response line is sent, followed by *Server* and *Date* headers. The values for these two headers are picked up from the :meth:`version_string` and :meth:`date_time_string` methods, respectively. .. method:: send_header(keyword, value) Writes a specific HTTP header to the output stream. *keyword* should specify the header keyword, with *value* specifying its value. .. method:: end_headers() Sends a blank line, indicating the end of the HTTP headers in the response. .. method:: log_request([code[, size]]) Logs an accepted (successful) request. *code* should specify the numeric HTTP code associated with the response. If a size of the response is available, then it should be passed as the *size* parameter. .. method:: log_error(...) Logs an error when a request cannot be fulfilled. By default, it passes the message to :meth:`log_message`, so it takes the same arguments (*format* and additional values). .. method:: log_message(format, ...) Logs an arbitrary message to ``sys.stderr``. This is typically overridden to create custom error logging mechanisms. The *format* argument is a standard printf-style format string, where the additional arguments to :meth:`log_message` are applied as inputs to the formatting. The client address and current date and time are prefixed to every message logged. .. method:: version_string() Returns the server software's version string. This is a combination of the :attr:`server_version` and :attr:`sys_version` class variables. .. method:: date_time_string([timestamp]) Returns the date and time given by *timestamp* (which must be in the format returned by :func:`time.time`), formatted for a message header. If *timestamp* is omitted, it uses the current date and time. The result looks like ``'Sun, 06 Nov 1994 08:49:37 GMT'``. .. versionadded:: 2.5 The *timestamp* parameter. .. method:: log_date_time_string() Returns the current date and time, formatted for logging. .. method:: address_string() Returns the client address, formatted for logging. A name lookup is performed on the client's IP address. More examples ------------- To create a server that doesn't run forever, but until some condition is fulfilled:: def run_while_true(server_class=BaseHTTPServer.HTTPServer, handler_class=BaseHTTPServer.BaseHTTPRequestHandler): """ This assumes that keep_running() is a function of no arguments which is tested initially and after each request. If its return value is true, the server continues. """ server_address = ('', 8000) httpd = server_class(server_address, handler_class) while keep_running(): httpd.handle_request() .. seealso:: Module :mod:`CGIHTTPServer` Extended request handler that supports CGI scripts. Module :mod:`SimpleHTTPServer` Basic request handler that limits response to files actually under the document root.
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