Python 2.7 sublist of nested list not working

Question

I am getting some strange results with extracting sublist.

list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

Switching the first and second index produces the same results.

list[:][1]
Out[8]: [4, 5, 6]

list[1][:]
Out[9]: [4, 5, 6]

and if I do this, it gives me an error

list[0:1][1]
Traceback (most recent call last):

  File "<ipython-input-10-93d72f916672>", line 1, in <module>
 list[0:1][1]

IndexError: list index out of range

Is this some known error with python 2.7?

Answer 1

When you slice a list say 0:5, list will get sliced excluding list[5]

Ex : l = [0,1,2,3,4,5]
l = l[0:5]
now l is [0,1,2,3,4]

Its same situation here, so its only 0th element present in list that is your list after slice is [[1,2,3]], which means 0th element is [1,2,3] and 1st element is out of range.!

Answer 2

If you observe the Slice list[0:1], It creates a list of size one, Also in Python indexing starts from 0 therefore, accessing index 1 of list with size one will raise an Error list index out of range

list = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]  //Original List

list[0:1] // [[1,2,3]]   A list of size 1

list[0:1][1] // This will return list index out of range

list[0:1][0]  // [1,2,3]