Is Dictionary a Built in Data Structure in Python?

Python is a versatile programming language that comes with a wide range of built-in data structures. These data structures allow programmers to efficiently store and manipulate data. One commonly used data structure in Python is the dictionary.

What is a Dictionary?

A dictionary is an unordered collection of key-value pairs. Each key-value pair in a dictionary is separated by a colon (:), and the pairs are enclosed in curly braces {}. Dictionaries are also sometimes referred to as associative arrays or hash maps.

How to Create a Dictionary

To create a dictionary in Python, you can use the following syntax:

• Create an empty dictionary: my_dict = {}
• Create a dictionary with initial values: my_dict = {'key1': value1, 'key2': value2}

Note that the keys in a dictionary must be unique, but the values can be duplicated.

Accessing Values in a Dictionary

You can access the values stored in a dictionary by using their corresponding keys. For example:

  # Create a dictionary
  my_dict = {'name': 'John', 'age': 25, 'city': 'New York'}

  # Access values
  name = my_dict['name']
  age = my_dict['age']
  city = my_dict['city']

  # Print values
  print(name)    # Output: John
  print(age)     # Output: 25
  print(city)    # Output: New York
  

Built-in Functions for Dictionaries

Python provides several built-in functions that can be used to perform various operations on dictionaries:

• len(): Returns the number of key-value pairs in a dictionary.
• keys(): Returns a list of all the keys in a dictionary.
• values(): Returns a list of all the values in a dictionary.
• items(): Returns a list of all the key-value pairs in a dictionary as tuples.

# Using built-in functions
print(len(my_dict)) # Output: 3
print(my_dict.keys()) # Output: [‘name’, ‘age’, ‘city’]
print(my_dict.values()) # Output: [‘John’, 25, ‘New York’]
print(my_dict.items()) # Output: [(‘name’, ‘John’), (‘age’, 25), (‘city’, ‘New York’)]

Modifying and Deleting Dictionary Elements

Dictionaries are mutable, which means you can modify their elements by assigning new values to specific keys. You can also delete elements from a dictionary using the del keyword.

# Modifying elements
my_dict[‘age’] = 26
my_dict[‘city’] = ‘San Francisco’

# Deleting elements
del my_dict[‘name’]

# Print modified dictionary
print(my_dict) # Output: {‘age’: 26, ‘city’: ‘San Francisco’}

Conclusion

In conclusion, a dictionary is indeed a built-in data structure in Python. It allows you to store and retrieve data efficiently using key-value pairs.

Dictionaries are versatile and widely used in various programming scenarios. By understanding how dictionaries work and utilizing their built-in functions, you can leverage the power of this data structure to write more efficient and organized Python code.