En Fri, 09 Apr 2010 01:13:37 -0300, Alf P. Steinbach <al...@start.no>
escribió:
> <code language="Py3">
> import urllib.request # urlopen
> import codecs # getreader
> import sys # stderr
>
> def text_stream_from( url, encoding ):
> text_reader = codecs.getreader( encoding )
> connection = urllib.request.urlopen( url )
> return text_reader( connection )
>
> def list_text( url, encoding ):
> lines = text_stream_from( url, encoding )
> for line in lines:
> print( line, end = "" )
> lines.close() # Undocumented?
>
> url = "http://www.rfc-editor.org/rfc/rfc1149.txt";
> list_text( url, "ascii" )
> </code>
>
> First, I'm unable to find documentation that there /is/ a close method
in the
> text_reader object, and I'm unable to find documentation that there is
a close
> method in the file like connection object; is there such documentation?
codecs.getreader returns a StreamReader instance (see [1])
StreamReader is documented here [2] and it says "In addition to the above
methods, the StreamReader must also inherit all other methods and
attributes from the underlying stream." -- the stream being 'connection',
from urllib.request.urlopen.
The 3.x version of the documentation in [3] doesn't provide any details
except being "a file-like object". The 2.x version [4] is much more clear:
"a file-like object is returned. This supports the following methods:
read(), readline(), readlines(), fileno(), close(), info(), getcode() and
geturl(). It also has proper support for the iterator protocol."
[1] http://docs.python.org/py3k/library/codecs.html#codecs.getreader
[2] http://docs.python.org/py3k/library/codecs.html#codecs.StreamReader
[3]
http://docs.python.org/py3k/library/urllib.request.html#urllib.request.urlopen
[4] http://docs.python.org/library/urllib.html#urllib.urlopen
> Second, I'm unable to find documentation of when they're called and
what they
> do. It seems that (A) when the connection object's st
method is called automatically, and (B) that when the
> text_reader object's close method is called it calls the close method
of the
> wrapped stream (i.e. on the connection object). But where is this
documented?
Nowhere, AFAIK.
I bet documentation patches are welcome.
--
Gabriel Genellina
--
http://mail.python.org/mailman/listinfo/python-list
