Resuming a program's execution after correcting error

[MRAB]

Sheldon wrote:
> Hi.
>
> Does anyone know if one can resume a python script at the error point
> after the error is corrected?
> I have a large program that take forever if I have to restart from
> scratch everytime. The error was the data writing a file so it seemed
> such a waste if all the data was lost and must be recalculated again.
>
You could modify the program while you're debugging it so that instead
of, say:

    calculate data
    write data

you have:

    if saved data exists:
        load data
    else:
        calculate data
        save data
    write data

The pickle module would be useful here.

Matthew