GET请求正常但其他请求报API Gateway内部服务器错误求助

问题现象 #

• GET请求通过Postman发送可正常收到"GET TEST"响应
• POST、PUT、DELETE请求均返回"API Gateway : Internal server error"
• 已在API Gateway对应资源上配置好上述请求方法

关联Lambda代码（已移除数据库凭证及游标初始化代码） #

import json
import mysql.connector

def lambda_handler(event, context):

    http_method = event.get('httpMethod')
    response = None  
    
    if http_method == "GET":
        response = getFunction(cursor, event)
    elif http_method == "POST":
         response = postFunction(cursor, event) 
    elif http_method == "PUT":
         response = putFunction(cursor, event)
    elif http_method == "DELETE":
         response = deleteFunction(cursor, event) 
        
  
    return {
        "statusCode": 200,
        "body": json.dumps({
            "event": event,
            "response": response
        })
    }

def getFunction(cursor, event):
    return "GET TEST"
    
def postFunction():
    return "POST TEST"
    
def putFunction():
    return "PUT TEST"

def deleteFunction():
    return "DELETE TEST"

错误根因 #

POST、PUT、DELETE对应的函数定义未声明参数，但在lambda_handler中调用时传入了cursor和event两个参数，导致函数调用时参数不匹配，触发运行时异常，最终被API Gateway返回500内部错误。

另外注意：当前代码中cursor变量未初始化（因移除了数据库相关代码），GET请求暂时正常是因为getFunction未实际使用该参数，但后续若需操作数据库，需补充cursor初始化逻辑，否则GET请求也会触发错误。

修复方案 #

方案1：调整函数定义匹配调用传参 #

修改POST/PUT/DELETE函数的定义，使其接收调用时传入的参数：

def postFunction(cursor, event):
    return "POST TEST"
    
def putFunction(cursor, event):
    return "PUT TEST"

def deleteFunction(cursor, event):
    return "DELETE TEST"

方案2：调整调用逻辑匹配函数定义 #

如果这些函数不需要cursor和event参数，直接修改lambda_handler中的调用代码：

if http_method == "GET":
    response = getFunction(cursor, event)
elif http_method == "POST":
     response = postFunction() 
elif http_method == "PUT":
     response = putFunction()
elif http_method == "DELETE":
     response = deleteFunction() 

内容的提问来源于stack exchange，提问作者Derkel