Lists in Python

Introduction

Lists in Python are analogous to arrays in Perl. A list holds a set of entities which could be strings or numbers. A list can in fact contain another list.
Declaring a list is fairly straight forward. Type the list name followed by the assignment operator (=) and then the list of items in square brackets separated by a comma.

>>> list=[1,2,3,4,'sahil']
>>> print list
[1, 2, 3, 4, 'sahil']
>>>

To access an individual element in the list type list_name[index]. Note that the indices start from 0 and not 1.

>>> print list[4]

sahil

>>>

Modifying lists:

There are a number of operations we can perform on lists to manipulate them. Here are a couple of examples.

Adding an element to a list:

>>> print list

[1, 2, 3, 4, 'sahil']

>>> list +=["hello"]

>>> print list

[1, 2, 3, 4, 'sahil', 'hello']

>>>

Substituting an element in the list:

>>> list=[1,2,3,4,'sahil']

>>> list[2]=9

>>> print list

[1, 2, 9, 4, 'sahil']

Replacing multiple items in a list:

>>> list[1:3]=[7,8]

>>> print list

[1, 7, 8, 4, 'sahil']

>>>

>>> list=[1, 7, 8, 4, 'sahil']

>>> list[1:2]=[2,3]

>>> print list

[1, 2, 3, 8, 4, 'sahil']

>>>

Removing multiple items in a list:

>>> list[1:3]=[]

>>> print list

[1, 4, 'sahil']

>>>

Add an element using append function:

>>> list.append('world')

>>> print list

[1, 2, 3, 8, 4, 'sahil', 'world']

>>>

Remove list element using pop function:

>>> list.pop(2)

3

>>> print list

[1, 2, 8, 4, 'sahil', 'world']

>>>

Remove list element using it's value:

>>> list.remove('sahil')

>>> print list

[1, 2, 8, 4, 'world']

>>>

Conclusion

This concludes our discussion on lists in Python. We hope that you found this quick and simple explanation to be useful.