How do you add breakpoints to a Python program in IDLE?
Completing the answer supplied by the OP: after setting the breakpoint - you must turn on IDLE's debug mode (using debug --> debugger). When you run the program, press "Go" in the debug window that opens up and IDLE will stop at the breakpoint.
There is an open Python issue about the lack of documentation for IDLE breakpoints. Contributions welcome!
Update: The on-line documentation and the IDLE help files (for 2.7.4, 3.2.4, and 3.3.0) have been updated, with Nick's help.
You can set breakpoint before it is run.
- Set the breakpoint by right clicking on the relevant line of your program
- On your python shell, look for Debug - [Debug On] will be shown in your IDLE Python shell
- Go back to your program and press F5(hotkey) to run the program, it will stop in the relevant break line(s)
- If you want to look at some global variables or line of codes, you can check the box in the debugger