Hmm. Evidently I didn't explain that very well. In ipython you're working in a REPL. Say you have a good many classes loaded up with data but some function deep inside one of them isn't producing the correct output. You can debug as you normally would inside the REPL. Use a debugger, deconstruct the function etc. When you get to the end you now have a fix for your function. Make that change in your file and, thanks to auto reload all of the objects in memory are immediately running the fixed function. You can then carry on working with the objects as though the bug was never there.
Depending on your scenario this can be a major win. On my project it's not uncommon for it to take 10 minutes to load and process that data from disk to get it into objects in memory. For me I can do that once and then carry on working with my data an code all in unison.
Whatever works for you. I'm pleased with my current environment on the server-side. It works very well for me.
I think chii was referring to a much more sophisticated REPL experience which doesn't require blowing away application state. This is possible in truly live environments like Smalltalk (checkout Squeak) or a competent Lisp environment. You can incrementally update your program from your editor and keep going all without reloading. This is how ClojureScript developers interact via the browser REPL for example.
Ah ok, fair enough. I'd heard that Smalltalk had a really good environment for this but I've never looked into it.
Let me rephrase then. There are amazing server side REPLs that allow me to change code on the fly, why can't I change code in my editor and have it reflected directly in my browser?
Depending on your scenario this can be a major win. On my project it's not uncommon for it to take 10 minutes to load and process that data from disk to get it into objects in memory. For me I can do that once and then carry on working with my data an code all in unison.
Whatever works for you. I'm pleased with my current environment on the server-side. It works very well for me.