os.system and quoted strings

[zefciu]

svata wrote:
> Hello,
> 
> as I'm new to python I've stumbled accros os.system and its not very
> well documented usage.
> 
> I use Win XP Pro and Python 2.5.
> 
> Here is the code snippet:
> 
> --------------------------------------------------------------------------------------------------
> 
> import time
> import os
> 
> dir = "C:\\Documents and Settings\\somepath\\"
> fileName = time.strftime("%d%m%Y")
> os.system('gvim dir+fileName+".txt"')
> 
> ---------------------------------------------------------------------------------------------------
> 
> The problem is that concatenated variable dir+fileName doesn't get
> expanded as expected.
> 
> Is there anything I omitted?
> 
> svata
> 

The way you write it, Python has no idea that dir and fileName are
variables, not literal parts of the string.  You should put those names
outside the quotation marks, or better us the % format operator as
Sriram showed
you, or even better use os.path module.  Here is the reference:
http://docs.python.org/lib/module-os.path.html

zefciu