[Python-talk] Accessing Web site via Python

[Peter Courlis]

Hello

Trying to run a script.py in Python25
on WinXP machine.

Using Command line, can do:
>>>print "hello world"
hello world
>>>
so, interpreter works OK

Next, put script (see bottom of this msg) into folder at
C:\python25\work

script saved as:
aapl.py

type at Cmd line:
>>>execfile aapl.py
syntax error line 1
  Name error: name 'aapl' is not defined

also tried:
type at Cmd line:
>>>execfile(aapl.py)      // note parens
syntax error line 1
  Name error: name 'aapl' is not defined

put copy of script into Dir:
C:\python25

because assumed we had a path problem?
tried above execute and execfile commands
with same errors?

so, what did I miss ?

signed: 

Python NewBie

Bill Sconce <sconce at in-spec-inc.com> wrote: On Fri, 4 May 2007 06:06:19 -0700 (PDT)
Peter Courlis  wrote:

> Good Morning,
> 
> A Python question?
> 
> I would like to  be able to go to a Web Site and 
> grab a piece of data. For example, to go to
> a specific Yahoo Finance page such as, 
> URL:http://finance.yahoo.com/q?s=AAPL
>   [...]
> Is there a mechanism, methods or library code in Python to
> perform this capture without writing spaghetti code?
> 
> Thanks in advance
> 
> Jim


Hi, Peter (Jim?) -

Yes there is.  For how you might pull down the HTML, see below.

Lloyd (the guy who signs his name as "Python") is right about parsing HTML;
i.e., using BeautifulSoup.  And of course what you do with the quote data
after you've extracted them may be any of a number of different processes. 

The code below should give you a flavor of Python.  It works.  (Although you
probably don't want to be hitting Yahoo! every 5 seconds...  :)

-Bill

P.S.  Do come around and hang out on the list, as Lloyd suggests.  You'll
be welcome.  And welcome at our PySIG meetings too!

_____________________________________________________________________
#! /usr/bin/env python2.5
"""Demonstrate one possible beginning to solving Jim Courlis's poser
   about Python and the Web.
   (c) In Spec, Inc., Milford, NH 03055-0085 USA.
   Released under GPL V2.
"""
import urllib2, time

def get_AAPL():
    """Get and return current AAPL quote from Yahoo! Finance page.
    
    Use ad-hoc parse based on simple manual inspection of the page.
    """
    quote_reader = urllib2.urlopen('http://finance.yahoo.com/q?s=AAPL')
    for text in quote_reader:
        whereis = text.find('class="ygtb">Apple Inc. (AAPL)')
        if whereis > -1:
            # HTML where quote appears looks like "102.88"
            start, end = '', ''
            start = text.find(start, whereis) + len(start)
            end = text.find('', start)
            quote_reader.close()
            return text[start:end]


if __name__ == '__main__':
    # Unit-test by getting and displaying a few quotes every 5 seconds
    more = 3
    while 1:
        print 'AAPL now trading at', get_AAPL()
        more -= 1
        if more:
            time.sleep(5)
        else:
            break


       
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
 Check outnew cars at Yahoo! Autos.
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