usage error

environment: windows xp cmd and python34
when execute "usage", error happend as below shows:
F:\mytest>python34 testJCP.py
Traceback (most recent call last):
  File "C:\Python34\lib\site-packages\json_config_parser-0.1.0-py3.4.egg\jsoncon
figparser.py", line 423, in read_string
  File "C:\Python34\lib\json\decoder.py", line 361, in raw_decode
    raise ValueError(errmsg("Expecting value", s, err.value)) from None
ValueError: Expecting value: line 10 column 7 (char 128)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "testJCP.py", line 21, in <module>
    """)
  File "C:\Python34\lib\site-packages\json_config_parser-0.1.0-py3.4.egg\jsoncon
figparser.py", line 427, in read_string
jsonconfigparser.JSONError: Line: 10, in section
  nil = nil
JSONError: Expecting value

after deleted "nail = nail" line, everything is ok