(Background: I am new to Google App Engine, familiar with other cloud providers\' services)
I am looking for access/view similar to shell access to production node.
If you are using the standard environment, the answer is no, you can't really inspect or see the code directly. You've mentioned looking at it via Stackdriver Debugger, which is one way to see a representation of it.
It sounds like if you have a reason to be looking at the code, then someone in your organization should grant you the appropriate level of access to your source code management system. I'd imagine if you're deployment practices are mature, then they'd likely branch the code to map to your deployed versions and you could inspect in detail locally.