How can I import regex on AWS Lambda
A new version of htmldate makes some of the dependencies optional, regex is such a case. That should solve the problem. (FYI: I'm the main developer of the package.)
I am getting the following error: 

Unable to import module '': No module
  named 'regex._regex'

The AWS Lambda deployment package runs just fine without import htmldate statement (the module I want to use) which in turn requires regex.
Also the code runs fine locally.  
So this seems to be a problem running regex on AWS Lambda.