Python语言词法分析api调用返回 {'log_id': ************************, 'error_code': 282004, 'error_msg': 'invalid parameter(s)'}

import requests
req_url = "https://aip.baidubce.com/rpc/2.0/nlp/v1/lexer?"
alter_charset = "charset=UTF-8"
access_token = "自己的access_token"
url = req_url + alter_charset + "&access_token=" + access_token
header = {"Content-Type": "application/json"}
text = "百度是一家高科技公司"
params = {"text": text}
res = requests.post(url=url, headers=header, data=params)
print(res.status_code)
print(res.json())

如代码，post内容为params

返回结果

200
{'log_id': ************************, 'error_code': 282004, 'error_msg': 'invalid parameter(s)'}