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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def process_file(self, path, dryrun):
 """ Print files path. """

        # if dryrun just return files
        if dryrun:
            return path

        # scan file and match lines
        ret = []
        with open(path, "r") as infile:
            for line in infile:
                if re.search(self.__exp, line):
                    ret.append(line)

        # if found matches return list of lines, else return None
        return ret if len(ret) > 0 else None