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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 update_repos(self):
 """Update repositories.conf file with enabled or disabled repositories """

        with open("{0}{1}".format(self.meta.conf_path,
                                  self.repositories_conf), "w") as new_conf:
            for line in self.conf.splitlines():
                line = line.lstrip()
                if self.tag in line:
                    self.tag_line = True
                if self.tag_line and line.startswith("#"):
                    repo = "".join(line.split("#")).strip()
                    if repo in self.selected:
                        new_conf.write(line.replace(line, repo + "\n"))
                        continue
                if (self.tag_line and not line.startswith("#") and
                        line != self.tag):
                    repo = line.strip()
                    if repo not in self.selected:
                        new_conf.write(line.replace(line, "# " + line + "\n"))
                        continue
                new_conf.write(line + "\n")