Python Dictionaries Explained: Day 5 Tutorial

Introduction:

Welcome to Day 5 of my Python journey!

Today, I explored the fascinating world of data structures in Python, specifically dictionaries. These data types are crucial for storing and manipulating complex data.

Dictionary predefine class / data type / data structure

---

• \ dict () → dictionary*

dict () is predefine class.

len () is used to get length of dictionary class .

help (dict) is used to get manual about dictionary class .

dict collection of pair of elements ( key & value ), but don’t divided with :

dict elements can be represent with in {} .

it is a iterable object .

it is a immutable object (hashable) .

it is mapping object .

key cannot be duplicate if duplicate it overwrite with last value but value may be duplicate.

definition using class:

• key can be all immutable object like (int, float, complex, none, bool, str, tuple & frozenset)

• but value can be all types.

Index/key :

• dictionary does not support index, it supports key.

• key is used to get value inside dictionary & update value inside dictionary

• invalid key return keyError

Dictionary predefine class:

predefine function :

all predefine functions only works with keys.

example:-

sobj ={'regno':1 , "name":"Raja Roy" , "dept":"Cs", "gender":"male", 'email':'raja19@gmail.com' }

print("length of dict =", len ( sobj ))

print ("max =", len ( sobj ))

print ("max =", max ( sobj ))

print ("min =", min ( sobj ))

#print ("sum =", sum ( sobj )) #error (all key are in string format)

print ("asc sort =", sorted ( sobj )) asc → ascending

print ("desc sort =", sorted ( sobj, reverse = True )) desc → descending

predefine method:

• get() : return value of given key

• keys() : return list of all key

• values() : return list of all values

• items () : return pair of elements

• pop() : remove value from dict of given keys

• popitem() : remove pair of element (key:value) from last position

• setdefault() : add a new key in a dict without value

• update() : update value

• clear() : delete all element from dict

• copy() : move a shallow copy

example:-

sobj = {'regno': 1, "name": "Raja Roy", "gender": "male"}

print (sobj , len (sobj))

sobj .setdefault ('dept')

print (sobj , len (sobj))

exam = {'c': 67, 'evs':65, 'dl':62}

sobj .update (exam)

sobj .update ({'dept':"Bca", 'name': "sita kant"})

print (sobj , len (sobj))

print ('list of keys=' , sobj .keys () )

print ('list of values=', sobj .values () )

print ('each pair of items=', sobj .items () )

print(sobj .pop ('dl'))

print (sobj.popitem ())

print (sobj)

print ("c marks =", sobj .get ('c'))

lobj = sobj .copy ()

print (lobj)

lobj .clear ()

print (lobj)

Challenges:

1. Understanding list comprehension.

2. Handling dictionary key errors.

Resources:

1. Official Python Documentation: Data Structures

2. W3Schools' Python Tutorial: Dictionaries

3. Scaler’s Python Course: Data Structures

Goals for Tomorrow:

1. Explore sets and frozensets.

Conclusion:

Day 5 was a blast! Dictionaries are now under my belt.

What are your favorite data structures in Python? Share in the comments below.

Connect with me:

LinkedIn: [https://www.linkedin.com/in/archana-prusty-4aa0b827a/]

GitHub: [https://github.com/p-archana1]

Join the conversation:

Share your own learning experiences or ask questions in the comments.

Next Post:

Day 6 : Sets, Frozensets .

Happy Learning!!

THANK YOU.