On Wed, Mar 19, 2008 at 2:21 PM, royG <[EMAIL PROTECTED]> wrote: > hi > i am trying to rename extension of files in a directory..as an initial > step i made a method in > > class ConvertFiles: > def __init__(self,infldr,outfldr): > self.infldr=infldr > self.outfldr=outfldr > self.origlist=os.listdir(infldr) > .... > def renamefiles(self,extn): > for x in self.origlist: > x=x+"."+extn > > ... > > later when i print self.origlist i find that the elements of list are > unchanged..even tho a print x inside the renamefiles() shows that > extn is appended to x .. > why does this happen?
Your 'x=' line is building a brand new string, and rebinding the name 'x' to it. It's not doing anything to the original list. See <http://effbot.org/zone/python-objects.htm>. I'd rewrite that as (untested): def renamefiles(self, extn): self.origlist = list((x + "." + extn) for x in self.origlist) or def renamefiles(self, extn): self.origlist = list(("%s.%s" % (z, extn)) for x in self.origlist) Better still, take a look at the os.path module... -- Cheers, Simon B. [EMAIL PROTECTED] http://www.brunningonline.net/simon/blog/ GTalk: simon.brunning | MSN: small_values | Yahoo: smallvalues -- http://mail.python.org/mailman/listinfo/python-list
