5. BaseHTTPServer — Basic HTTP server¶

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 SimpleHTTPServer and CGIHTTPServer modules.

The first class, HTTPServer, is a SocketServer.TCPServer subclass, and therefore implements the 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 BaseHTTPServer.HTTPServer(server_address, RequestHandlerClass)[source]¶

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.

class BaseHTTPServer.BaseHTTPRequestHandler(request, client_address, server)[source]¶

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). 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.

command¶

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

path¶

Contains the request path.

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.

rfile¶

Contains an input stream, positioned at 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.

BaseHTTPRequestHandler has the following class variables:

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 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.

error_content_type¶

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

New in version 2.6: Previously, the content type was always 'text/html'.

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 send_header()) in all of its responses to clients. For backwards compatibility, the setting defaults to 'HTTP/1.0'.

MessageClass¶

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()