Wing's Debug Probe is a powerful auto-completing Python Shell that can be used in the context of the current debug stack frame. It may be used to quickly investigate the causes of a bug, and allows crafting of code fragments in the live runtime context for which the fix is being designed.
The Debug Probe is useful even for new code: Just set a breakpoint in the context where the new code is to run and try out code fragments in the Debug Probe. The auto-completer and Source Assistant are fueled by the actual runtime state, making this an efficient and accurate way to develop and try out code in an unfamiliar or tricky runtime environment.
For more information, see Interactive Debug Probe.