Breakpoints

Breakpoints can be set and cleared by clicking in the required line, and then clicking the breakpoint tool. Alternatively, use any of the left-hand windows to find a function, and right-click; the popup menu will contain options to set a breakpoint (execution freezes when a breakpoint is hit) or set a watchpoint (watchpoints simply count the number of times thay have been hit).

Once a breakpoint is encountered, you can continue execution (execution continues until either another breakpoint is encountered, an exception is trapped, or control exits from the python script, or you can single step, in which case execution continues to until control arrives on a new line. Strictly, new line means when the python interpreter reports that control as reached a new line. In the case of a statement like while i < 10 : i = i + j, the same line will be repeatedly executed while i is less than ten, so a breakpoint on this line may be trapped several times in succession.

You can also abort execution after a breakpoint. Actually, this raises a python exception, so if the python script catches the exception, execution will continue from that point.