This content originally appeared on DEV Community and was authored by Aditi Sharma
Understanding the Differences Between List, Tuple, Set, and Dictionary
After completing Python’s core data structures, I decided to summarize the main differences between them. These are the building blocks of Python, and knowing when to use each makes a big difference in writing clean & efficient code.
1. List
• Ordered
• Mutable (can change after creation)
• Allows duplicates
• Best for collections that need modification
my_list = [1, 2, 2, 3]
my_list.append(4)
print(my_list) # [1, 2, 2, 3, 4]
2. Tuple
• Ordered
• Immutable (cannot be changed after creation)
• Allows duplicates
• Best for fixed collections (e.g., coordinates, settings)
my_tuple = (1, 2, 3)
print(my_tuple[0]) # 1
3. Set
• Unordered
• Mutable (can add/remove items)
• No duplicates
• Best for uniqueness, filtering, and set operations
my_set = {1, 2, 2, 3}
print(my_set) # {1, 2, 3}
4. Dictionary
• Unordered (Python 3.7+ keeps insertion order)
• Mutable
• Key-Value pairs
• Keys must be unique, values can repeat
• Best for fast lookups and mappings
my_dict = {“name”: “Alice”, “age”: 25}
print(my_dict[“name”]) # Alice
| Feature | List | Tuple | Set | Dictionary |
|---|---|---|---|---|
| Ordered |  |
|
 |
(insertion order) |
| Mutable | |
|
|
|
| Duplicates | |
|
|
Keys , Values |
| Use Case | Dynamic collection | Fixed collection | Unique items | Key-value mapping |
Reflection
Understanding these four data structures has given me a strong foundation in Python. Now I can choose the right structure for the right problem, which is crucial in data analytics and real-world programming.
Next up → I’ll start exploring Python libraries that make coding even more powerful. 
Python #DataStructures #100DaysOfCode #DevCommunity #LearningJourney
This content originally appeared on DEV Community and was authored by Aditi Sharma