Question

I have the following code that’s looping through files in a folder and doing a simple search and replace, and then outputs the results to a different folder. What I am noticing is that the replace string seems to be getting applied twice.

For example:

Search string: foo

Replace string: foo bar

Result: foo bar bar

Here is my code. I’m sure the problem is obvious, but I just can’t put my finger on it.

def SearchReplace(directory, search, replace, filePattern):
    for path, dirs, files in os.walk(os.path.abspath(directory)):
        for filename in fnmatch.filter(files, filePattern):
            filepath = os.path.join(path, filename)
            outfile = os.path.join(outputdir, filename)
            with open(filepath) as f:
                s = f.read()
            s = s.replace(search, replace)
            with open(outfile, "w") as f:
                f.write(s)
SearchReplace(inputdir, searchstr, replacestr, ext)

NOTE: if I do not output the results to a separate folder, the search/replace performs as expected. Meaning, the code below works fine (modifies input file in same folder):

def SearchReplace(directory, search, replace, filePattern):
    for path, dirs, files in os.walk(os.path.abspath(directory)):
        for filename in fnmatch.filter(files, filePattern):
            filepath = os.path.join(path, filename)
            with open(filepath) as f:
                s = f.read()
            s = s.replace(search, replace)
            with open(filepath, "w") as f:
                f.write(s)
SearchReplace(inputdir, searchstr, replacestr, ext)

However, I need to output the results to a separate folder.

Answer 1

The problem is that your output folder is included in the input search pattern, so the replacement is made once on the input file, then again on the output file.