Pycharm has a build in debugger, however, there are some tricky problems described below.

Breaking on Exception¶

Breaking on exception is one of the most important debugger tools. However, there are some problems with Pycharm exception debugging.

Breake on Termination vs on Raise¶

By default, the program breakes on termination (unhandled exception). This is usually a correct configuration. However, in jupyter, all exceptions are caught to not break the jupyter itself. Therefore, in jupyter, all exceptions are ignored by the debugger if the breakpoins are set to break on termination.

To break on exceptions in jupyter, we have to breake on raise. By this setting, however, we stop even on expected/handeled exceptions, stoping potentially on hundereds breakpoints in library code.

Another issue is with the setting itself. To propagate the change between breaking on raise/termination, we have to deactivate and then activate again the exception breakpoints, otherwise, the setting is ignored.