One thing that I find to be incredibly useful is the keyboard shortcut `00` (press zero twice while focus is outside of a cell), which will restart the kernel,

One thing that I find to be incredibly useful is the keyboard shortcut `00` (press zero twice while focus is outside of a cell), which will restart the kernel, clear all output and re-run the whole notebook. This way I'm sure that "library code" that I'm editing in parallel in a real text editor is up to date in the notebook and also solves the limits the confusion due to run-out-of-oder problems. The overall workflow is something like this: 1. explore using thing.<TAB>, thing?, and %psource thing 2. edit draft code chunk or function 3. when chunk 80% done; move it to a module and replace it with an import statement 4. press 00 to re-run everything, then GOTO step 1 The key to preserving sanity is step 3—as soon as the exploration phase is done, move to a real text editor (and start adding tests). Don't try to do big chunks of software development in the notebook. You wouldn't write an entire program in the REPL, would you? Sometimes I keep around the notebook as a record for failed explorations or as a "test harness" for the code, but most of the time it's throwoutable since all the useful bits have moved into a normal python module/script under version control.