Do a search-and-replace across all files in a folder through python?

Question

I'd like to learn to use python as a command line scripting replacement. I spent some time with python in the past but it's been a while. This seems to be within the scope of it.

I have several files in a folder that I want to do a search-and-replace on, within all of them. I'd like to do it with a python script.

For example, search and replace all instances of "foo" with "foobar".

Answer 1

Welcome to StackOverflow. Since you want to learn yourself (+1) I'll just give you a few pointers.

Check out os.walk() to get at all the files.

Then iterate over each line in the files (for line in currentfile: comes in handy here).

Now you need to know if you want a "stupid" replace (find/replace each foo even if it's in the middle of a word (say foobar - do you want foofoobar as a result?) or a smart replace.

For the former, look at str.replace(), for the latter, look at re.sub() and figure out what r'\bfoo\b' means.