more Pythonic solution

        result = run(cmd, logger=logger)

        # parse output

        tmp_string = re.findall(r'Input level:\s+[-+]?(?:\d*\.*\d+)', result.stdout)[0]

        measured_loudness = float(tmp_string.split(":")[1])

        tmp_string = re.findall(r'Scaling factor:\s+[-+]?(?:\d*\.*\d+)', result.stdout)[0]

        scale_factor = float(tmp_string.split(":")[1])

        # we are looking for the (floating-point) number after the search string - '( )' around the number denotes the first group

        measured_loudness = float(re.search(r'Input level:\s+([-+]?(?:\d*\.*\d+))', result.stdout).group(1))

        scale_factor = float(re.search(r'Scaling factor:\s+([-+]?(?:\d*\.*\d+))', result.stdout).group(1))

    return measured_loudness, scale_factor