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09 DICTIONARY IN
PYTHON
Your Aim
to learn about:
Creating a Dictionary Accessing a Dictionary
Python Methods Python Functions
Updating a Dictionary Removing or Deleting Elements of a Dictionary
Some More Programs
A dictionary in Python is another data type which contains a collection of values in the form of key
value pairs. Instead of using indexing, it uses keys to access the elements. It is a heterogeneous
collection of data elements, where key must be unique and immutable. All the elements of a
dictionary are enclosed within a pair of curly brackets {}.
In the previous chapters, you have learned Python lists and tuples. In this chapter you will learn
about Python dictionary, how to create a dictionary and operations performed on it.
CREATING A DICTIONARY
To create a dictionary in Python use the following syntax:
d = {key1: value1, key2 : value2, ... }
Example:
d2 = {’width’: 8.5, ’height’: 11}
d3 = {1: ’RED’, 2: ’GREEN’, 3: ’BLUE’, }
Program 1: To create a dictionary.
Program1.py
File Edit Format Run Options Window Help
dict1={'Name': 'A', 'Rollno': 1}
print(dict1)
dict2={'Name': 'B', 'Rollno': 2, 'Marks': [15, 47, 54] }
print(dict2)
dict3=dict({'Name': 'C', 'Rollno': 3})
print(dict3)
dict4=dict([('Name', 'D'), ('Rollno', 4)])
print(dict4)
Dictionary in Python 101

