Resuming a program's execution after correcting error

[Sheldon]

MRAB wrote:
> Sheldon wrote:
> > MRAB wrote:
> > > 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
> >
> > I like your idea Matthew but I don't know how to pickle the many
> > variables in one file. Do I need to pickle each and every variable into
> > a seperate file?
> > var1,var2
> > pickle.dump(var1,f)
> > pickle.dump(var2,f2)
> >
> Using the 'pickle' module:
>
>     # To store:
>     f = open(file_path, "wb")
>     pickle.dump(var1, f)
>     pickle.dump(var2, f)
>     f.close()
>
>     # To load
>     f = open(file_path, "rb")
>     var1 = pickle.load(f)
>     var2 = pickle.load(f)
>     f.close()
>
> A more flexible alternative is to use the 'shelve' module. This behaves
> like a dict:
>
>     # To store
>     s = shelve.open(file_path)
>     s["var1"] = "first"
>     s["var2"] = [2, 3]
>     s.close()
>
>     # To load
>     s = shelve.open(file_path)
>     print s["var1"] # This prints "first"
>     print s["var2"] # This prints [2, 3]
>     s.close()
>
> Hope that helps
> Matthew

Perfect Matthew!

Much obliged!

/Sheldon