Often times I want to edit a whole slew of files at once, changing only a simple string. But it's the same change in all the files.
The solution for this has eluded me till now (worst yet.. it's a simple solution. A classic one liner.)
[perl] perl -pi.bak -e 's/oldstring/newstring/' *.py [/perl]
Simply put this changes every occurrence of "oldstring" to "newstring" in .py saving the original files as .py.bak
then verify it did what you wanted and delete the .bak files