he most basic data structure in Python is the sequence. Each element of a sequence is assigned a number – its position or index. The first index is zero, the second index is one, and so forth.

Python has six built-in types of sequences, but the most common ones are lists and tuples
Types — str, unicode, list, tuple, buffer, xrange

There are certain things you can do with all sequence types. These operations include indexing, slicing, adding, multiplying, and checking for membership. In addition, Python has built-in functions for finding the length of a sequence and for finding its largest and smallest elements.

lists are created using [ and ]
li = [1,2,3,4]

accessing list values: list[index]

li⁰ for first element.

updating the list:
li² = 3

deleting list:
del li³ – to delete 4th element.
del li – to delete list

Basic list operations:
: [1,2,3][4,3,2] o/p [1,2,3,4,3,2]

• : repeat [1,2]*3 = [1,2,1,2,1,2]
  len(li) : length of a list
  2 in [1,2,3,4,4] : members in the list
  iteration : for x in li print(x)

Built-in List Functions & Methods
Python includes the following list functions −

Sr.No. Function with Description
1 cmp(list1, list2) : Compares elements of both lists.

2 len(list): Gives the total length of the list.

3 max(list): Returns item from the list with max value.

4 min(list): Returns item from the list with min value.

5 list(seq): Converts a tuple into list.

Python includes following list methods

Sr.No. Methods with Description
1 list.append(obj)
Appends object obj to list

2 list.count(obj)
Returns count of how many times obj occurs in list

3 list.extend(seq)
Appends the contents of seq to list

4 list.index(obj)
Returns the lowest index in list that obj appears

5 list.insert(index, obj)
Inserts object obj into list at offset index

6 list.pop(obj=list[-1])
Removes and returns last object or obj from list

7 list.remove(obj)
Removes object obj from list

8 list.reverse()
Reverses objects of list in place

9 list.sort([func])
Sorts objects of list, use compare func if given