python - Lambda 和 Lex 集成没有从字符串值反序列化的字符串参数构造函数/工厂方法

Question

我是 Lex 与 Lambda 集成的新手，之前在 Connect 中使用过 lambda，但不确定为什么此示例代码在我身上失败并且不理解错误消息。

我在 Lex 中设置了两个插槽（empid 和 fever）。机器人的话语启动，然后我收到错误消息，而不是“请输入您的员工 ID？”的问题。

import json

def build_response(message):
    return {
        "dialogAction":{
            "type":"Close",
            "fulfillmentState":"Fulfilled",
            "message":{
                "contentType":"PlainText",
                "content":message
            }
        }
    }

def elicit_slot(intent_name, slots, slot_to_elicit, message):
    return {
        'dialogAction': {
            'type': 'ElicitSlot',
            'intentName': intent_name,
            'slots': slots,
            'slotToElicit': slot_to_elicit,
            'message': message
        }
    }

def delegate(session_attributes, slots):
    return {
        'sessionAttributes': session_attributes,
        'dialogAction': {
            'type': 'Delegate',
            'slots': slots
        }
    }

def perform_action(intent_request):
    source = intent_request['invocationSource']   # DialogCodeHook or FulfillmentCodeHook
    slots = intent_request['currentIntent']['slots']  # your slots 
    if source == 'DialogCodeHook':
        # Perform basic validation on the supplied input slots.
        if slots['empid'] is None:  # or any other validation that you want to perform
            return elicit_slot(
                intent_request['currentIntent']['name'], # current intent name
                slots, # current intent slots
                'empid',  # slot name
                'Please enter your employee id'  # prompt the user to empid
            )
        if slots['fever'] is None:
            return elicit_slot(
                intent_request['currentIntent']['name'], # current intent name
                slots, # current intent slots
                'fever',  # slot name
                'Do you have a fever?' # prompt the answer do you have a fever
            )
        # delegate means all slot validation are done, we can move to Fulfillment
        return delegate(output_session_attributes, slots) 
    if source == 'FulfillmentCodeHook':
        #result = your_api_call(slots['city'], slots['country'])
        result = "Your employee id is you answered to having a fever."
        return build_response(result)  # display the response back to user

def dispatch(intent_request):
    intent_name = intent_request['currentIntent']['name']
    # Dispatch to your bot's intent handlers
    if intent_name == 'covidqs':
        return perform_action(intent_request)
    raise Exception('Intent with name ' + intent_name + ' not supported')

def lambda_handler(event, context):
    #logger.debug(event)
    return dispatch(event)

收到此错误：

An error has occurred: Invalid Lambda Response: Received invalid response from Lambda: Can not construct instance of Message: no String-argument constructor/factory method to deserialize from String value ('Please enter your employee id') at [Source: {"dialogAction": {"type": "ElicitSlot", "intentName": "covidqs", "slots": {"empid": null, "fever": null}, "slotToElicit": "empid", "message": "Please enter your employee id"}}; line: 1, column: 143]

标签： pythonaws-lambdaaws-lex

Answer 1

我想通了。消息响应必须采用特定格式。那么它在哪里

"message": message 

应该是

"message":{
    "contentType":"PlainText",
    "content":message
 }