the return of urllib.request.urlopen("http://www.example.com/", params)

Steven D'Aprano steven at REMOVE.THIS.cybersource.com.au
Wed Apr 1 06:49:30 CEST 2009


On Tue, 31 Mar 2009 21:17:29 -0700, tunpishuang wrote:

> hey guys , i'm new in python ...here i got a little problem that get me
> confused...
> i wanna do an uthentication of an login page , here is the example from
> the python lib ref. :
> 
>>>> import urllib.request
>>>> import urllib.parse
>>>> params = urllib.parse.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0}) f
>>>> = urllib.request.urlopen("http://www.musi-cal.com/cgi-bin/query?%s" %
>>>> params) print(f.read())
> 
> i wanted to know what the the return value of f ,,if it's an instance of
> http.client.HTTPResponse
> and why the return source of the web page is quote like this :
> 
> b'<html></html>'


Looks like you are using Python 3.0.

In Python 2.x, the native string type is bytes (commonly called "ASCII"). 
So a string of bytes is displayed like this:

'abcdef...'

and a string of Unicode characters is displayed like this:

u'abcdef...'


In Python 3.0, the native string type is unicode, but HTTP responses are 
bytes. Bytes are displayed like this:

b'abcdef...'

and strings of characters like this:

'abcdef...'

Notice that the B on the outside of the quotes is not part of the string, 
it is part of the display format, just like the quotes themselves.


You can convert the bytes into a string by just called str() on the 
output:

# untested
>>> print(str(f.read()))
'<html></html>'

This should work for the simple case, although once you start getting 
more complicated strings, with international (non-English) characters, 
you will need to supply an encoding.


Does this help?



-- 
Steven



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