Mutable Sequence Types in Python


Mutable Sequence Types

  • List
  • Dictionary
  • Set

Mutable Sequence Types and Immutable Sequence Types objects are treated differently in python. Immutable objects are faster to access and are costlier to change because it needs the creation of a copy.

Whereas mutable objects are easy to change.


In Python, the data structure or we can say sequences are defined into two categories –
  • Mutable Sequences
  • Immutable Sequences
Mutable sequences can be changed after their creation while immutable sequences can’t be updated however there are some tricks to update the immutable sequences. So, due to the above characteristics, immutable sequences are read-only and mutable sequences are both read and write compatible.



>>> companies = ['tata','wipro','accenture']
>>> companies
['tata', 'wipro', 'accenture']
>>> companies[0]='tcs'
>>> companies
['tcs', 'wipro', 'accenture']
>>> companies[-1]='cognizant'
>>> companies
['tcs', 'wipro', 'cognizant']


>>> dictionary1 = {'Prep':'Insta', 1:'Myname'}
>>> dictionary1
{'Prep': 'Insta', 1: 'Myname'}
>>> dictionary1['Prep']='PrepInsta'
>>> dictionary1
{'Prep': 'PrepInsta', 1: 'Myname'}
>>> dictionary1[0]='Prep'
{'Prep': 'PrepInsta', 1: 'Myname', 0: 'Prep'}


>>> set1=set(companies)
>>> set1
{'wipro', 'tcs', 'cognizant'}
>>> set1.add('accenture')
>>> set1
{'accenture', 'wipro', 'tcs', 'cognizant'}

For questions on List, Dictionary, Set click on given button.