A list is created by adding comma separated values in [ ]
list1 = ['a', 'b', 1, 2];
list2 = [1, 2, 3, 4, 5, 6, 7 ];
print "list1[0]: ", list1[0]
print "list2[1:5]: ", list2[1:5]
Output:
list1[0]: a
list2[1:5]: [2,3,4,5]
You can update the value simply by assigning new value:
list2[3] = 8
print "list2[3]: ", list2[3]
Output:
list2[3]: 8
Hope this helps.