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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 _parse_repo_file(filename):
    '''
    Turn a single repo file into a dict
    '''
    parsed = configparser.ConfigParser()
    config = {}

    try:
        parsed.read(filename)
    except configparser.MissingSectionHeaderError as err:
        log.error(
            'Failed to parse file %s, error: %s',
            filename, err.message
        )
        return ('', {})

    for section in parsed._sections:
        section_dict = dict(parsed._sections[section])
        section_dict.pop('__name__', None)
        config[section] = section_dict

    # Try to extract header comments, as well as comments for each repo. Read
    # from the beginning of the file and assume any leading comments are
    # header comments. Continue to read each section header and then find the
    # comments for each repo.
    headers = ''
    section = None
    with salt.utils.files.fopen(filename, 'r') as repofile:
        for line in repofile:
            line = salt.utils.stringutils.to_unicode(line)
            line = line.strip()
            if line.startswith('#'):
                if section is None:
                    headers += line + '\n'
                else:
                    try:
                        comments = config[section].setdefault('comments', [])
                        comments.append(line[1:].lstrip())
                    except KeyError:
                        log.debug(
                            'Found comment in %s which does not appear to '
                            'belong to any repo section: %s', filename, line
                        )
            elif line.startswith('[') and line.endswith(']'):
                section = line[1:-1]

    return (headers, salt.utils.data.decode(config))