Help doing it the "python way"

[Paul Rubin]

Paul Rubin <no.email at nospam.invalid> writes:
>     new_list = chain( ((x,y-1), (x,y+1)) for x,y in coord_list )

Sorry:

   new_list = list(chain( ((x,y-1), (x,y+1)) for x,y in coord_list))