How to integrate Lambda, Alexa, and my code (Python - Tweepy)?
For your question about capturing user's input for tweeting, use AMAZON.SearchQuery slot type.  You may run into limitations about how much text can be collected and the quality of the capture but SearchQuery slot is the place to start.
I am trying to tweet something by talking to Alexa. I want to put my code on AWS Lambda, and trigger the function by Alexa.
I already have a Python code that can tweet certain string successfully. And I also managed to create a zip file and deploy it on Lambda (code depends on the "tweepy" package). However, I could not get to trigger the function by Alexa, I understand that I need to use handlers and ASK-SDK (Alexa Service Kit), but I am kind of lost at this stage. Could anyone please give me an idea about how the handlers work and help me see the big picture?