Documentation updates for urllib package. Modified the documentation for the
urllib,urllib2 -> urllib.request,urllib.error
urlparse -> urllib.parse
RobotParser -> urllib.robotparser
Updated tutorial references and other module references (http.client.rst,
ftplib.rst,contextlib.rst)
Updated the examples in the urllib2-howto
Addresses Issue3142.
diff --git a/Doc/library/urllib.error.rst b/Doc/library/urllib.error.rst
new file mode 100644
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+:mod:`urllib.error` --- Exception classes raised by urllib.request
+==================================================================
+
+.. module:: urllib.error
+ :synopsis: Next generation URL opening library.
+.. moduleauthor:: Jeremy Hylton <jhylton@users.sourceforge.net>
+.. sectionauthor:: Senthil Kumaran <orsenthil@gmail.com>
+
+
+The :mod:`urllib.error` module defines exception classes raise by
+urllib.request. The base exception class is URLError, which inherits from
+IOError.
+
+The following exceptions are raised by :mod:`urllib.error` as appropriate:
+
+
+.. exception:: URLError
+
+ The handlers raise this exception (or derived exceptions) when they run into a
+ problem. It is a subclass of :exc:`IOError`.
+
+ .. attribute:: reason
+
+ The reason for this error. It can be a message string or another exception
+ instance (:exc:`socket.error` for remote URLs, :exc:`OSError` for local
+ URLs).
+
+
+.. exception:: HTTPError
+
+ Though being an exception (a subclass of :exc:`URLError`), an :exc:`HTTPError`
+ can also function as a non-exceptional file-like return value (the same thing
+ that :func:`urlopen` returns). This is useful when handling exotic HTTP
+ errors, such as requests for authentication.
+
+ .. attribute:: code
+
+ An HTTP status code as defined in `RFC 2616 <http://www.faqs.org/rfcs/rfc2616.html>`_.
+ This numeric value corresponds to a value found in the dictionary of
+ codes as found in :attr:`http.server.BaseHTTPRequestHandler.responses`.
+
+.. exception:: ContentTooShortError(msg[, content])
+
+ This exception is raised when the :func:`urlretrieve` function detects that the
+ amount of the downloaded data is less than the expected amount (given by the
+ *Content-Length* header). The :attr:`content` attribute stores the downloaded
+ (and supposedly truncated) data.
+