Slicing a list with non-integer parameter? How?

[Husam]

Hi fiends,
I'm trying to determine the position of an item in a list in order to
delete it by slicing the list with non integer parameter.
Code I works just fine. But code II doe's not work:

Code 1 with integer values:

>> list1=[1,2,3,4]
>>> for i in list1:
...     if i==2:
...             pos=len(list)-len(list[i:])
...             del list[pos-1]
...             print list
...
[1, 3, 4]

Code II with non integer values:

>>> list2=['one','two','thrie','four']
>>> for i in list2:
...     if i=='drie':
...             pos=len(list)-len(list[i:])
...             del list[pos-1]
...             print list
...
Traceback (innermost last):
  File "<stdin>", line 3, in ?
TypeError: slice index must be int


PS: my Python version is 1.5

thanks in advance