От PDB
(Pdb) help l
l(ist) [first [,last]]
List source code for the current file.
Without arguments, list 11 lines around the current line
or continue the previous listing.
With one argument, list 11 lines starting at that line.
With two arguments, list the given range;
if the second argument is less than the first, it is a count.
Функция "продолжить предыдущий список" действительно хороша, но как вы ее отключите?