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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 repodata_files(self, channels=None):
 """ Return the repodata paths based on `channels` and the `data_directory`. There is no check for validity here. """

        if channels is None:
            channels = self.conda_get_condarc_channels()

        repodata_urls = self._set_repo_urls_from_channels(channels)

        repopaths = []

        for repourl in repodata_urls:
            fullpath = os.sep.join([self._repo_url_to_path(repourl)])
            repopaths.append(fullpath)

        return repopaths