人工智能——nlp自学习平台如何python调用api？

# 创建AcsClient实例
print 'done1_______________'
client = AcsClient('xxx', 'xxxx', 'cn-hangzhou')
print 'done2_______________'
request = CommonRequest()
print 'done3_______________'
request.set_domain("automl.cn-hangzhou.aliyuncs.com") # 必须设置domain
print 'done4_______________'
request.set_uri_pattern("/api/automl/predict") #设置所要请求的API路径
print 'done5_______________'
request.set_method(method_type.POST); # 设置请求方式，目前只支持POST
print 'done6_______________'
request.add_header("ModelId", "663")
request.add_header("Version", "V1")
request.add_header("Content-Type", "application/json") # 设置签名方法
print 'done7_______________'
request.add_header("x-acs-signature-nonce", uuid.uuid4().hex)# 设置请求唯一码，防止网络重放攻击, 每个请求必须不同
print 'done8_______________'
request.add_header("x-acs-signature-version", "1.0") # 设置签名版本
print 'done9_______________'
#request.add_header("content", "gut")
content = '{"content": "pretty good."}'
print 'done10_______________'
request.set_content_type("application/json;chrset=utf-8")  # 设置请求格式
print 'done11_______________'
request.set_accept_format("application/json;chrset=utf-8") # 设置响应格式
print 'done12_______________'
request.set_content(content.encode('utf-8')) # 设置请求内容
print 'done13_______________'
request.set_version('2019-05-29') # 设置版本
print 'done14_______________'
request.set_action_name("None")
print 'done15_______________'
try:
    response = client.do_action_with_exception(request)
except ServerException as e:
    # 这里可以添加您自己的错误处理逻辑
    # 例如，打印具体的错误信息
    print e.get_http_status()
    print e.get_error_code()
    print e.get_error_msg()
#response = client.do_action_with_exception(request)
print 'done16_______________'
#print response

我从网上找了一个模板，然后按照手册里面的帮助改
这个model是我拿nlp自学习平台文本分类做好的一个情感分析model
报错说
400
MissingContent
Content is mandatory for this action.
改了半天了还是这样，想请教各位爸爸怎么办呀o(╥﹏╥)o