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author | Guido van Rossum <guido@python.org> | 1995-02-16 16:29:46 (GMT) |
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committer | Guido van Rossum <guido@python.org> | 1995-02-16 16:29:46 (GMT) |
commit | a8db1df6aac4782a80c36bf25a8d26c1c327f13e (patch) | |
tree | fa53a50c0bd2ad1fce9893c649183e6db7d78042 /Doc/lib | |
parent | ed2bad8ef85c7a7a233c9d44238323b9ed81c28d (diff) | |
download | cpython-a8db1df6aac4782a80c36bf25a8d26c1c327f13e.zip cpython-a8db1df6aac4782a80c36bf25a8d26c1c327f13e.tar.gz cpython-a8db1df6aac4782a80c36bf25a8d26c1c327f13e.tar.bz2 |
document www interfaces
Diffstat (limited to 'Doc/lib')
-rw-r--r-- | Doc/lib/liburllib.tex | 102 | ||||
-rw-r--r-- | Doc/lib/libwww.tex | 45 |
2 files changed, 147 insertions, 0 deletions
diff --git a/Doc/lib/liburllib.tex b/Doc/lib/liburllib.tex new file mode 100644 index 0000000..49bc416 --- /dev/null +++ b/Doc/lib/liburllib.tex @@ -0,0 +1,102 @@ +\section{Built-in module \sectcode{urllib}} +\stmodindex{urllib} +\index{WWW} +\indexii{World-Wide}{Web} +\index{URLs} + +This module provides a high-level interface for fetching data across +the World-Wide Web. In particular, the \code{urlopen} function is +similar to the built-in function \code{open}, but accepts URLs +(Universal Resource Locators) instead of filenames. Some restrictions +apply --- it can only open URLs for reading, and no seek operations +are available. + +it defines the following public functions: + +\begin{funcdesc}{urlopen}{url} +Open a network object denoted by a URL for reading. If the URL does +not have a scheme identifier, or if it has \code{file:} as its scheme +identifier, this opens a local file; otherwise it opens a socket to a +server somewhere on the network. If the connection cannot be made, or +if the server returns an error code, the \code{IOError} exception is +raised. If all went well, a file-like object is returned. This +supports the following methods: \code{read()}, \code{readline()}, +\code{readlines()}, \code{fileno()}, \code{close()} and \code{info()}. +Except for the last one, these methods have the same interface as for +file objects --- see the section on File Objects earlier in this +manual. + +The \code{info()} method returns an instance of the class +\code{rfc822.Message} containing the headers received from the server, +if the protocol uses such headers (currently the only supported +protocol that uses this is HTTP). See the description of the +\code{rfc822} module. +\end{funcdesc} + +\begin{funcdesc}{urlretrieve}{url} +Copy a network object denoted by a URL to a local file, if necessary. +If the URL points to a local file, or a valid cached copy of the the +object exists, the object is not copied. Return a tuple (\var{filename}, +\var{headers}) where \var{filename} is the local file name under which +the object can be found, and \var{headers} is either \code{None} (for +a local object) or whatever the \code{info()} method of the object +returned by \code{urlopen()} returned (for a remote object, possibly +cached). Exceptions are the same as for \code{urlopen()}. +\end{funcdesc} + +\begin{funcdesc}{urlcleanup}{} +Clear the cache that may have been built up by previous calls to +\code{urlretrieve()}. +\end{funcdesc} + +Restrictions: + +\begin{itemize} + +\item +Currently, only the following protocols are supported: HTTP, (versions +0.9 and 1.0), Gopher (but not Gopher-+), FTP, and local files. +\index{HTTP} +\index{Gopher} +\index{FTP} + +\item +The caching feature of \code{urlretrieve()} has been disabled until I +find the time to hack proper processing of Expiration time headers. + +\item +There should be an function to query whether a particular URL is in +the cache. + +\item +For backward compatibility, if a URL appears to point to a local file +but the file can't be opened, the URL is re-interpreted using the FTP +protocol. This can sometimes cause confusing error messages. + +\item +The \code{urlopen()} and \code{urlretrieve()} functions can cause +arbitrarily long delays while waiting for a network connection to be +set up. This means that it is difficult to build an interactive +web client using these functions without using threads. + +\item +The data returned by \code{urlopen()} or \code{urlretrieve()} is the +raw data returned by the server. This may be binary data (e.g. an +image), plain text or (for example) HTML. The HTTP protocol provides +type information in the reply header, which can be inspected by +looking at the \code{Content-type} header. For the Gopher protocol, +type information is encoded in the URL; there is currently no easy way +to extract it. If the returned data is HTML, you can use the module +\code{htmllib} to parse it. +\index{HTML} +\index{HTTP} +\index{Gopher} +\stmodindex{htmllib} + +\item +Although the \code{urllib} module contains (undocumented) routines to +parse and unparse URL strings, the recommended interface for URL +manipulation is in module \code{urlparse}. +\stmodindex{urlparse} + +\end{itemize} diff --git a/Doc/lib/libwww.tex b/Doc/lib/libwww.tex new file mode 100644 index 0000000..5cd4c05 --- /dev/null +++ b/Doc/lib/libwww.tex @@ -0,0 +1,45 @@ +\chapter{WORLD-WIDE WEB EXTENSIONS} +\index{WWW} +\indexii{World-Wide}{Web} + +The modules described in this chapter provide various services to +World-Wide Web (WWW) clients and/or services, and a few modules +related to news and email. They are all implemented in Python. Some +of these modules require the presence of the system-dependent module +\code{sockets}, which is currently only fully supported on Unix and +Windows NT. Here is an overview: + +\begin{description} + +\item[urllib] +--- Open an arbitrary object given by URL (requires sockets). + +\item[httplib] +--- HTTP protocol client (requires sockets). + +\item[ftplib] +--- FTP protocol client (requires sockets). + +\item[gopherlib] +--- Gopher protocol client (requires sockets). + +\item[nntplib] +--- NNTP protocol client (requires sockets). + +\item[urlparse] +--- Parse a URL string into a tuple (addressing scheme identifier, network +location, path, parameters, query string, fragment identifier). + +\item[htmllib] +--- A (slow) parser for HTML files. + +\item[sgmllib] +--- Only as much of an SGML parser as needed to parse HTML. + +\item[rfc822] +--- Parse RFC-822 style mail headers. + +\item[mimetools] +--- Tools for parsing MIME style message bodies. + +\end{description} |