Try this:
pt = list()
pt.append(raw_input())
pt.append(raw_input())
print pt
You now have two elements in your list. Once you are more familiar with python syntax, you might write this as:
pt = [raw_input(), raw_input()]
Also, note that lists are not to be confused with arrays in Java or C: Lists grow dynamically. You don't have to declare the size when you create a new list.
BTW: I tried out your example in the interactive shell. It works, but probably not as you expected:
>>> pt = [2]
>>> pt[0] = raw_input()
1011
>>> pt
['1011']
I'm guessing you thought pt = [2] would create a list of length 2, so a pt[1] = raw_input() would fail like you mentioned:
>>> pt = [2]
>>> pt[0] = raw_input()
1011
>>> pt[1] = raw_input() # this is an assignment to an index not yet created.
1012
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
IndexError: list assignment index out of range
Actually, pt = [2] creates a list with one element, having the value 2 at index 0:
>>> pt = [2]
>>> pt
[2]
>>>
So you can assign to the index 0 as demonstrated above, but assigning to index 1 will not work - use append for appending to a list.