How to Use Python Dictionaries

09/08/2021

Contents

In this article, you will learn how to use Python dictionaries.

Python Dictionaries

Python dictionaries are key-value pairs that store values in an unordered and mutable way. You can use dictionaries to store and retrieve data in a flexible way.

Here are some common ways to use dictionaries in Python:

Creating a dictionary

You can create a dictionary using curly braces {} or the dict() constructor.

For example:

# Using curly braces
my_dict = {'key1': 'value1', 'key2': 'value2'}

# Using dict() constructor
my_dict = dict(key1='value1', key2='value2')

Accessing values

You can access values stored in a dictionary using the square bracket syntax and the key name.

For example:

my_dict = {'key1': 'value1', 'key2': 'value2'}
print(my_dict['key1'])  # Output: value1

Adding/Updating values

You can add a new key-value pair to the dictionary or update the value of an existing key using the square bracket syntax.

For example:

my_dict = {'key1': 'value1', 'key2': 'value2'}

# Adding a new key-value pair
my_dict['key3'] = 'value3'

# Updating the value of an existing key
my_dict['key2'] = 'new_value2'

Deleting values

You can delete a key-value pair from a dictionary using the del statement or the pop method.

For example:

my_dict = {'key1': 'value1', 'key2': 'value2'}

# Using del statement
del my_dict['key1']

# Using pop method
my_dict.pop('key2')

Looping through a dictionary

You can loop through the keys, values, or both of a dictionary using the items method.

For example:

my_dict = {'key1': 'value1', 'key2': 'value2'}

# Looping through keys
for key in my_dict.keys():
    print(key)

# Looping through values
for value in my_dict.values():
    print(value)

# Looping through both keys and values
for key, value in my_dict.items():
    print(key, value)

These are just a few of the ways you can use dictionaries in Python. There are many more methods and features available to make dictionaries even more flexible and useful.

#Python