No module named 'awscam' Traceback - Deeplens / Lambda

Hi, I am building a simple application using Aamzon Deeplens. When compiling the Lambda function which interact with deeplens, it keep poping up the error "Unable to import module 'greengrassHelloWorld': No module named 'awscam' Traceback". I have reinstall awscam and updated the software on Deeplens for multiple times. I even tested the Deeplens Lambda template that is provoided by AWS. It still shows the same error. Please advise.