<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def read_config_file(libname):
 """ Extract library locations from a configuration file. Parameters libname : str One of either 'openjp2' or 'openjpeg' Returns ------- path : None or str None if no location is specified, otherwise a path to the library """

    filename = glymurrc_fname()
    if filename is None:
        # There's no library file path to return in this case.
        return None

    # Read the configuration file for the library location.
    parser = ConfigParser()
    parser.read(filename)
    try:
        path = parser.get('library', libname)
    except (NoOptionError, NoSectionError):
        path = None
    return path