Assigning output from a simple python statement

[Anthony J Wilkinson]

On 16 Mar 2000, Wilson Fletcher wrote:

> I would like to execute an unknown python statement and store the output.
> 
> It will typically be a print statement. eg. "print 'Hello World'"
> 
> I won't know the statement until runtime becuase it will come from a
> database. BUT I want to capture anything that goes to stdout and process
> it. 

I got the following (slight modifications made) from
<ftp://ftp.python.org/pub/python/mail/hypermail/python-recent/0759.html>
after a quick search on <http://www.python.org/search/> for 'redirect
stdout'

>>> import sys
>>> class Output:
...     def __init__(self):
...             self.text=""
...     def write(self, string):
...             self.text = self.text + string
...     def writelines(self, lines):
...             for lin in lines: self.write(line)
...     def close(self):
...             pass
...     def flush(self):
...             pass
...     def isatty(self):
...             return 0
... 
>>> cmdstr = "print 'Hello World'"
>>> oldstdout=sys.stdout
>>> sys.stdout=Output()
>>> exec cmdstr
>>> # Note I left the brackets off this time but I'm sure someone can
... # nitpick something else :-)
...
>>> result = sys.stdout.text
>>> sys.stdout = oldstdout
>>> print result
Hello World

Regards,
Anthony
_____________________________________________________________________
Anthony J Wilkinson                                  anthony at dstc.com
Software Engineer                                     http://dstc.com
DSTC Pty Ltd                                     Ph:  +61 7 3365 4310