\section{\module{BaseHTTPServer} --- Basic HTTP server} \declaremodule{standard}{BaseHTTPServer}\modulesynopsis{Basic HTTP server (base class for \class{SimpleHTTPServer} and \class{CGIHTTPServer}).} \indexii{WWW}{server}\indexii{HTTP}{protocol}\index{URL}\index{httpd} This module defines two classes for implementing HTTP servers(Web servers). Usually, this module isn't used directly, but is usedas a basis for building functioning Web servers. See the\refmodule{SimpleHTTPServer}\refstmodindex{SimpleHTTPServer} and\refmodule{CGIHTTPServer}\refstmodindex{CGIHTTPServer} modules. The first class, \class{HTTPServer}, is a\class{SocketServer.TCPServer} subclass. It creates and listens at theHTTP socket, dispatching the requests to a handler. Code to create andrun the server looks like this: \begin{verbatim}def run(server_class=BaseHTTPServer.HTTPServer, handler_class=BaseHTTPServer.BaseHTTPRequestHandler): server_address = ('', 8000) httpd = server_class(server_address, handler_class) httpd.serve_forever()\end{verbatim} \begin{classdesc}{HTTPServer}{server_address, RequestHandlerClass}This class builds on the \class{TCPServer} class bystoring the server address as instancevariables named \member{server_name} and \member{server_port}. Theserver is accessible by the handler, typically through the handler's\member{server} instance variable.\end{classdesc} \begin{classdesc}{BaseHTTPRequestHandler}{request, client_address, server}This class is usedto handle the HTTP requests that arrive at the server. By itself,it cannot respond to any actual HTTP requests; it must be subclassedto handle each request method (e.g. GET or POST).\class{BaseHTTPRequestHandler} provides a number of class and instancevariables, and methods for use by subclasses. The handler will parse the request and the headers, then call amethod specific to the request type. The method name is constructedfrom the request. For example, for the request method \samp{SPAM}, the\method{do_SPAM()} method will be called with no arguments. All ofthe relevant information is stored in instance variables of thehandler. Subclasses should not need to override or extend the\method{__init__()} method.\end{classdesc} \class{BaseHTTPRequestHandler} has the following instance variables: \begin{memberdesc}{client_address}Contains a tuple of the form \code{(\var{host}, \var{port})} referringto the client's address.\end{memberdesc} \begin{memberdesc}{command}Contains the command (request type). For example, \code{'GET'}.\end{memberdesc} \begin{memberdesc}{path}Contains the request path.\end{memberdesc} \begin{memberdesc}{request_version}Contains the version string from the request. For example,\code{'HTTP/1.0'}.\end{memberdesc} \begin{memberdesc}{headers}Holds an instance of the class specified by the \member{MessageClass}class variable. This instance parses and manages the headers inthe HTTP request.\end{memberdesc} \begin{memberdesc}{rfile}Contains an input stream, positioned at the start of the optionalinput data.\end{memberdesc} \begin{memberdesc}{wfile}Contains the output stream for writing a response back to the client.Proper adherence to the HTTP protocol must be used when writingto this stream.\end{memberdesc} \class{BaseHTTPRequestHandler} has the following class variables: \begin{memberdesc}{server_version}Specifies the server software version. You may want to overridethis.The format is multiple whitespace-separated strings,where each string is of the form name[/version].For example, \code{'BaseHTTP/0.2'}.\end{memberdesc} \begin{memberdesc}{sys_version}Contains the Python system version, in a form usable by the\member{version_string} method and the \member{server_version} classvariable. For example, \code{'Python/1.4'}.\end{memberdesc} \begin{memberdesc}{error_message_format}Specifies a format string for building an error response to theclient. It uses parenthesized, keyed format specifiers, so theformat operand must be a dictionary. The \var{code} key shouldbe an integer, specifying the numeric HTTP error code value.\var{message} should be a string containing a (detailed) errormessage of what occurred, and \var{explain} should be anexplanation of the error code number. Default \var{message}and \var{explain} values can found in the \var{responses}class variable.\end{memberdesc} \begin{memberdesc}{protocol_version}This specifies the HTTP protocol version used in responses. If setto \code{'HTTP/1.1'}, the server will permit HTTP persistentconnections; however, your server \emph{must} then include anaccurate \code{Content-Length} header (using \method{send_header()})in all of its responses to clients. For backwards compatibility,the setting defaults to \code{'HTTP/1.0'}.\end{memberdesc} \begin{memberdesc}{MessageClass}Specifies a \class{rfc822.Message}-like class to parse HTTPheaders. Typically, this is not overridden, and it defaults to\class{mimetools.Message}.\withsubitem{(in module mimetools)}{\ttindex{Message}}\end{memberdesc} \begin{memberdesc}{responses}This variable contains a mapping of error code integers to two-elementtuples containing a short and long message. For example,\code{\{\var{code}: (\var{shortmessage}, \var{longmessage})\}}. The\var{shortmessage} is usually used as the \var{message} key in anerror response, and \var{longmessage} as the \var{explain} key(see the \member{error_message_format} class variable).\end{memberdesc} A \class{BaseHTTPRequestHandler} instance has the following methods: \begin{methoddesc}{handle}{}Calls \method{handle_one_request()} once (or, if persistent connectionsare enabled, multiple times) to handle incoming HTTP requests.You should never need to override it; instead, implement appropriate\method{do_*()} methods.\end{methoddesc} \begin{methoddesc}{handle_one_request}{}This method will parse and dispatchthe request to the appropriate \method{do_*()} method. You shouldnever need to override it.\end{methoddesc} \begin{methoddesc}{send_error}{code\optional{, message}}Sends and logs a complete error reply to the client. The numeric\var{code} specifies the HTTP error code, with \var{message} asoptional, more specific text. A complete set of headers is sent,followed by text composed using the \member{error_message_format}class variable.\end{methoddesc} \begin{methoddesc}{send_response}{code\optional{, message}}Sends a response header and logs the accepted request. The HTTPresponse line is sent, followed by \emph{Server} and \emph{Date}headers. The values for these two headers are picked up from the\method{version_string()} and \method{date_time_string()} methods,respectively.\end{methoddesc} \begin{methoddesc}{send_header}{keyword, value}Writes a specific HTTP header to the output stream. \var{keyword}should specify the header keyword, with \var{value} specifyingits value.\end{methoddesc} \begin{methoddesc}{end_headers}{}Sends a blank line, indicating the end of the HTTP headers inthe response.\end{methoddesc} \begin{methoddesc}{log_request}{\optional{code\optional{, size}}}Logs an accepted (successful) request. \var{code} should specifythe numeric HTTP code associated with the response. If a size ofthe response is available, then it should be passed as the\var{size} parameter.\end{methoddesc} \begin{methoddesc}{log_error}{...}Logs an error when a request cannot be fulfilled. By default,it passes the message to \method{log_message()}, so it takes thesame arguments (\var{format} and additional values).\end{methoddesc} \begin{methoddesc}{log_message}{format, ...}Logs an arbitrary message to \code{sys.stderr}. This is typicallyoverridden to create custom error logging mechanisms. The\var{format} argument is a standard printf-style format string,where the additional arguments to \method{log_message()} are appliedas inputs to the formatting. The client address and current dateand time are prefixed to every message logged.\end{methoddesc} \begin{methoddesc}{version_string}{}Returns the server software's version string. This is a combinationof the \member{server_version} and \member{sys_version} class variables.\end{methoddesc} \begin{methoddesc}{date_time_string}{\optional{timestamp}}Returns the date and time given by \var{timestamp} (which must be in theformat returned by \function{time.time()}), formatted for a message header.If \var{timestamp} is omitted, it uses the current date and time. The result looks like \code{'Sun, 06 Nov 1994 08:49:37 GMT'}.\versionadded[The \var{timestamp} parameter]{2.5}\end{methoddesc} \begin{methoddesc}{log_date_time_string}{}Returns the current date and time, formatted for logging.\end{methoddesc} \begin{methoddesc}{address_string}{}Returns the client address, formatted for logging. A name lookupis performed on the client's IP address.\end{methoddesc} \begin{seealso} \seemodule{CGIHTTPServer}{Extended request handler that supports CGI scripts.} \seemodule{SimpleHTTPServer}{Basic request handler that limits response to files actually under the document root.}\end{seealso}
\section{\module{BaseHTTPServer} ---
Basic HTTP server}
\declaremodule{standard}{BaseHTTPServer}
\modulesynopsis{Basic HTTP server (base class for
\class{SimpleHTTPServer} and \class{CGIHTTPServer}).}
\indexii{WWW}{server}
\indexii{HTTP}{protocol}
\index{URL}
\index{httpd}
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
\refmodule{SimpleHTTPServer}\refstmodindex{SimpleHTTPServer} and
\refmodule{CGIHTTPServer}\refstmodindex{CGIHTTPServer} modules.
The first class, \class{HTTPServer}, is a
\class{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:
\begin{verbatim}
def run(server_class=BaseHTTPServer.HTTPServer,
handler_class=BaseHTTPServer.BaseHTTPRequestHandler):
server_address = ('', 8000)
httpd = server_class(server_address, handler_class)
httpd.serve_forever()
\end{verbatim}
\begin{classdesc}{HTTPServer}{server_address, RequestHandlerClass}
This class builds on the \class{TCPServer} class by
storing the server address as instance
variables named \member{server_name} and \member{server_port}. The
server is accessible by the handler, typically through the handler's
\member{server} instance variable.
\end{classdesc}
\begin{classdesc}{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 \samp{SPAM}, the
\method{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
\method{__init__()} method.
\end{classdesc}
\class{BaseHTTPRequestHandler} has the following instance variables:
\begin{memberdesc}{client_address}
Contains a tuple of the form \code{(\var{host}, \var{port})} referring
to the client's address.
\end{memberdesc}
\begin{memberdesc}{command}
Contains the command (request type). For example, \code{'GET'}.
\end{memberdesc}
\begin{memberdesc}{path}
Contains the request path.
\end{memberdesc}
\begin{memberdesc}{request_version}
Contains the version string from the request. For example,
\code{'HTTP/1.0'}.
\end{memberdesc}
\begin{memberdesc}{headers}
Holds an instance of the class specified by the \member{MessageClass}
class variable. This instance parses and manages the headers in
the HTTP request.
\end{memberdesc}
\begin{memberdesc}{rfile}
Contains an input stream, positioned at the start of the optional
input data.
\end{memberdesc}
\begin{memberdesc}{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.
\end{memberdesc}
\class{BaseHTTPRequestHandler} has the following class variables:
\begin{memberdesc}{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, \code{'BaseHTTP/0.2'}.
\end{memberdesc}
\begin{memberdesc}{sys_version}
Contains the Python system version, in a form usable by the
\member{version_string} method and the \member{server_version} class
variable. For example, \code{'Python/1.4'}.
\end{memberdesc}
\begin{memberdesc}{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 \var{code} key should
be an integer, specifying the numeric HTTP error code value.
\var{message} should be a string containing a (detailed) error
message of what occurred, and \var{explain} should be an
explanation of the error code number. Default \var{message}
and \var{explain} values can found in the \var{responses}
class variable.
\end{memberdesc}
\begin{memberdesc}{protocol_version}
This specifies the HTTP protocol version used in responses. If set
to \code{'HTTP/1.1'}, the server will permit HTTP persistent
connections; however, your server \emph{must} then include an
accurate \code{Content-Length} header (using \method{send_header()})
in all of its responses to clients. For backwards compatibility,
the setting defaults to \code{'HTTP/1.0'}.
\end{memberdesc}
\begin{memberdesc}{MessageClass}
Specifies a \class{rfc822.Message}-like class to parse HTTP
headers. Typically, this is not overridden, and it defaults to
\class{mimetools.Message}.
\withsubitem{(in module mimetools)}{\ttindex{Message}}
\end{memberdesc}
\begin{memberdesc}{responses}
This variable contains a mapping of error code integers to two-element
tuples containing a short and long message. For example,
\code{\{\var{code}: (\var{shortmessage}, \var{longmessage})\}}. The
\var{shortmessage} is usually used as the \var{message} key in an
error response, and \var{longmessage} as the \var{explain} key
(see the \member{error_message_format} class variable).
\end{memberdesc}
A \class{BaseHTTPRequestHandler} instance has the following methods:
\begin{methoddesc}{handle}{}
Calls \method{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
\method{do_*()} methods.
\end{methoddesc}
\begin{methoddesc}{handle_one_request}{}
This method will parse and dispatch
the request to the appropriate \method{do_*()} method. You should
never need to override it.
\end{methoddesc}
\begin{methoddesc}{send_error}{code\optional{, message}}
Sends and logs a complete error reply to the client. The numeric
\var{code} specifies the HTTP error code, with \var{message} as
optional, more specific text. A complete set of headers is sent,
followed by text composed using the \member{error_message_format}
class variable.
\end{methoddesc}
\begin{methoddesc}{send_response}{code\optional{, message}}
Sends a response header and logs the accepted request. The HTTP
response line is sent, followed by \emph{Server} and \emph{Date}
headers. The values for these two headers are picked up from the
\method{version_string()} and \method{date_time_string()} methods,
respectively.
\end{methoddesc}
\begin{methoddesc}{send_header}{keyword, value}
Writes a specific HTTP header to the output stream. \var{keyword}
should specify the header keyword, with \var{value} specifying
its value.
\end{methoddesc}
\begin{methoddesc}{end_headers}{}
Sends a blank line, indicating the end of the HTTP headers in
the response.
\end{methoddesc}
\begin{methoddesc}{log_request}{\optional{code\optional{, size}}}
Logs an accepted (successful) request. \var{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
\var{size} parameter.
\end{methoddesc}
\begin{methoddesc}{log_error}{...}
Logs an error when a request cannot be fulfilled. By default,
it passes the message to \method{log_message()}, so it takes the
same arguments (\var{format} and additional values).
\end{methoddesc}
\begin{methoddesc}{log_message}{format, ...}
Logs an arbitrary message to \code{sys.stderr}. This is typically
overridden to create custom error logging mechanisms. The
\var{format} argument is a standard printf-style format string,
where the additional arguments to \method{log_message()} are applied
as inputs to the formatting. The client address and current date
and time are prefixed to every message logged.
\end{methoddesc}
\begin{methoddesc}{version_string}{}
Returns the server software's version string. This is a combination
of the \member{server_version} and \member{sys_version} class variables.
\end{methoddesc}
\begin{methoddesc}{date_time_string}{\optional{timestamp}}
Returns the date and time given by \var{timestamp} (which must be in the
format returned by \function{time.time()}), formatted for a message header.
If \var{timestamp} is omitted, it uses the current date and time.
The result looks like \code{'Sun, 06 Nov 1994 08:49:37 GMT'}.
\versionadded[The \var{timestamp} parameter]{2.5}
\end{methoddesc}
\begin{methoddesc}{log_date_time_string}{}
Returns the current date and time, formatted for logging.
\end{methoddesc}
\begin{methoddesc}{address_string}{}
Returns the client address, formatted for logging. A name lookup
is performed on the client's IP address.
\end{methoddesc}
\begin{seealso}
\seemodule{CGIHTTPServer}{Extended request handler that supports CGI
scripts.}
\seemodule{SimpleHTTPServer}{Basic request handler that limits response
to files actually under the document root.}
\end{seealso}