Python reloading in repl

[guibou]

If you load some modules with pymain, such as:

          [pymain|
            import json
            import importlib
            
            import my_business_module

Unfortunately, even after a ghci reload (e.g. :reload), the python context stays initialised and hence the import are NOT reloaded. This can be confusing (I spent a bit of time tuning my haskell code and reloading without sucess and even with confusing errors before realizing that I needed to reload the repl).

A workaround is to use importlib to reload the modules:

          [pymain|
            import json
            import importlib
            
            import my_business_module
            importlib.reload(my_business_module)

That's a bit slower and comes with few gurantee (the reload model of python is not perfect), but it saves a full ghci reload in many context.

If you agree, I'll add a line in haddock in the section Troubleshooting.

[Shimuuar]

Please do