Emacs and pdb

M-x pdb

https://www.gnu.org/software/emacs/manual/html.../emacs/Commands-of-GUD.html

27.6.3 Commands of GUD. GUD provides commands for setting and clearing breakpoints, selecting stack frames, and stepping through the program. C-x C-a C-b: Set a breakpoint on the source line that point is on. C-x C-a C-b ( gud-break ), when called in a source buffer, sets a debugger breakpoint on the current source ...