selenium+python 语言编写问题，在执行时无法输入中文用户名

Traceback (most recent call last):
File "E:\workspace\test\src\management\test.py", line 16, in <module>
driver.find_element_by_name("login_name").send_keys("王国梁")
File "C:\Python27\lib\site-packages\selenium\webdriver\remote\webelement.py", line 303, in send_keys
self._execute(Command.SEND_KEYS_TO_ELEMENT, {'value': typing})
File "C:\Python27\lib\site-packages\selenium\webdriver\remote\webelement.py", line 385, in _execute
return self._parent.execute(command, params)
File "C:\Python27\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 171, in execute
response = self.command_executor.execute(driver_command, params)
File "C:\Python27\lib\site-packages\selenium\webdriver\remote\remote_connection.py", line 346, in execute
data = utils.dump_json(params)
File "C:\Python27\lib\site-packages\selenium\webdriver\remote\utils.py", line 30, in dump_json
return json.dumps(json_struct)
File "C:\Python27\lib\json\__init__.py", line 243, in dumps
return _default_encoder.encode(obj)
File "C:\Python27\lib\json\encoder.py", line 207, in encode
chunks = self.iterencode(o, _one_shot=True)
File "C:\Python27\lib\json\encoder.py", line 270, in iterencode
return _iterencode(o, 0)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xe7 in position 0: unexpected end of data