Client side Python and skulpt

[hugetim]

This gave me the idea for a feature request:

[DONE] An Anvil client-code REPL

One of the biggest drawbacks of Anvil for me has been the ambiguity about which features of Python are available in the client-side code based on Skulpt. Currently, the best way to know for sure seems to be to test out the code you want to use. (For instance, you can create an app with a Module as the startup and use print statements to double-check that that bit of Python is working as expected.) I wish there were a console-like REPL available in the context of each app to make this kind of gu…