list has a meaning in ptpdb.. it shouldnt

[ktaragorn]

list is also the list constructor

[haakenlid]

This is also the case with pdb from the standard library. I think the debugger commands are the same as in the GNU debugger (GDB) that has been around for several decades.

If a debugger command collides with a python identifier, you can use ! at the start of the line.

(Pdb) list
[EOF]
(Pdb) !list
<type 'list'>