How to get keys of dictionary in Python?

Getting Keys of Dictionary in Python

Introduction

In Python, dictionaries are a fundamental data structure that stores key-value pairs. They are used to store data in a flexible and efficient manner. One of the key features of dictionaries is that they allow you to access values by their corresponding keys. In this article, we will explore how to get keys of dictionary in Python.

Basic Dictionary Operations

Before we dive into getting keys of dictionary, let’s cover some basic dictionary operations:

• Creating a dictionary: You can create a dictionary using the dict() function or by assigning key-value pairs to a variable.
• Accessing values: You can access values by their corresponding keys using the square bracket notation dictionary[key].
• Updating values: You can update values by assigning a new value to a key using the assignment operator dictionary[key] = new_value.
• Deleting values: You can delete values by using the del statement.

Getting Keys of Dictionary

Now that we have covered basic dictionary operations, let’s focus on getting keys of dictionary.

Method 1: Using Dictionary Keys

You can get keys of dictionary using the keys() method.

# Create a dictionary

person = {'name': 'John', 'age': 30, 'city': 'New York'}



# Get keys of dictionary

keys = person.keys()



# Print keys

print(keys)  # Output: dict_keys(['name', 'age', 'city'])

Method 2: Using Dictionary Items

You can get keys of dictionary using dictionary items.

# Create a dictionary

person = {'name': 'John', 'age': 30, 'city': 'New York'}



# Get keys of dictionary

keys = list(person.items())



# Print keys

print(keys)  # Output: [('name', 'John'), ('age', 30), ('city', 'New York')]

Method 3: Using Dictionary Values

You can get keys of dictionary using dictionary values.

# Create a dictionary

person = {'name': 'John', 'age': 30, 'city': 'New York'}



# Get keys of dictionary

keys = list(person.values())



# Print keys

print(keys)  # Output: ['John', 30, 'New York']

Method 4: Using Dictionary Items as Keys

You can get keys of dictionary using dictionary items as keys.

# Create a dictionary

person = {'name': 'John', 'age': 30, 'city': 'New York'}



# Get keys of dictionary

keys = list(person.keys())



# Print keys

print(keys)  # Output: ['name', 'age', 'city']

Important Points

• Dictionary keys are immutable: Dictionary keys are immutable, meaning they cannot be changed after creation.
• Dictionary values are mutable: Dictionary values are mutable, meaning they can be changed after creation.
• Dictionary keys are unique: Dictionary keys are unique, meaning each key corresponds to a unique value.

Conclusion

In this article, we have explored how to get keys of dictionary in Python. We covered basic dictionary operations, including creating dictionaries, accessing values, updating values, and deleting values. We also discussed how to get keys of dictionary using dictionary keys, dictionary items, dictionary values, and dictionary items as keys. By understanding how to get keys of dictionary, you can efficiently store and retrieve data in your Python programs.

Table: Dictionary Operations

Operation	Description
Creating a dictionary	Assign key-value pairs to a variable or use the dict() function
Accessing values	Use the square bracket notation dictionary[key]
Updating values	Assign a new value to a key using the assignment operator dictionary[key] = new_value
Deleting values	Use the del statement

Code Snippets

# Create a dictionary

person = {'name': 'John', 'age': 30, 'city': 'New York'}



# Get keys of dictionary

keys = person.keys()



# Print keys

print(keys)  # Output: dict_keys(['name', 'age', 'city'])



# Get keys of dictionary using dictionary items

keys = list(person.items())



# Print keys

print(keys)  # Output: [('name', 'John'), ('age', 30), ('city', 'New York')]



# Get keys of dictionary using dictionary values

keys = list(person.values())



# Print keys

print(keys)  # Output: ['John', 30, 'New York']



# Get keys of dictionary using dictionary items as keys

keys = list(person.keys())



# Print keys

print(keys)  # Output: ['name', 'age', 'city']