Prototyping is what you usually do in ML/DS. You code incrementally and break things really fast. Python (IPython/Jupyter) and R's interactive mode is really i

Prototyping is what you usually do in ML/DS. You code incrementally and break things really fast. Python (IPython/Jupyter) and R's interactive mode is really indispensable for this. Without restarting/re-initialize every variables and modules from beginning, you can run code snippet, run, edit part of code, run, add some code, plot something, run, repeat...