Python Data Structures: Lists, Tuples, Sets and Dictionaries


  • A List is a dynamic array in Python, allowing you to store multiple different values, and elements can be changed after initialization.
  • To declare a List, use square brackets [].


# Declare a List containing integers
numbers = [1, 2, 3, 4, 5]

# Access and print elements in the List
print(numbers[0])  # Output: 1
print(numbers[2])  # Output: 3

# Modify the value of an element in the List
numbers[1] = 10
print(numbers)  # Output: [1, 10, 3, 4, 5]



  • A Tuple is an immutable data structure in Python, often used to protect data from being changed after initialization.
  • To declare a Tuple, use parentheses ().


# Declare a Tuple containing information of a student
student_info = ('John', 25, 'Male', 'New York')

# Access and print elements in the Tuple
print(student_info[0])  # Output: John
print(student_info[2])  # Output: Male



  • A Set is a data structure that does not contain duplicate elements and has no order.
  • To declare a Set, use curly braces {} or the set() function.


# Declare a Set containing colors
colors = {'red', 'green', 'blue', 'red', 'yellow'}

# Print the Set to check duplicate elements are removed
print(colors)  # Output: {'red', 'green', 'blue', 'yellow'}



  • A Dictionary is an unordered data structure that stores information in key-value pairs.
  • To declare a Dictionary, use curly braces {} and separate each key-value pair with a colon :.


# Declare a Dictionary containing information of a person
person = {'name': 'John', 'age': 30, 'city': 'New York'}

# Access and print values from the Dictionary
print(person['name'])  # Output: John
print(person['age'])   # Output: 30

# Modify the value of a key in the Dictionary
person['city'] = 'Los Angeles'
print(person)  # Output: {'name': 'John', 'age': 30, 'city': 'Los Angeles'}

These data structures allow programmers to manipulate and process data flexibly in Python, suitable for various programming scenarios and purposes.