🔑 Python Tutorial: Understanding Dictionaries in Python

Introduction

Dictionaries are Python’s built-in data structure for storing key-value pairs. They’re perfect for representing structured data like user profiles, settings, and JSON objects.

1. Creating a Dictionary

person = {"name": "Koikoi", "age": 25, "is_student": True}
print(person)

Try it yourself: Create a dictionary for your favorite book with title, author, and genre.

2. Accessing Values

print(person["name"])   # Koikoi
print(person["age"])    # 25

Exercise: Print the genre of your book dictionary.

3. Modifying Values

person["age"] = 26
print(person)

Challenge: Update one value in your dictionary.

4. Adding and Removing Keys

person["location"] = "Kenya"
del person["is_student"]
print(person)

Try it: Add a new key and remove an old one.

5. Looping Through Dictionaries

for key, value in person.items():
    print(key, ":", value)

Exercise: Loop through your book dictionary and print each key-value pair.

6. Real‑World Example: User Profile

user = {
  "username": "koikoi",
  "email": "koikoi@example.com",
  "verified": True
}
user["last_login"] = "2026-03-24"
for k, v in user.items():
    print(f"{k}: {v}")

Challenge: Add a new field like “subscription” and print the updated profile.

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Want to dive deeper? Check out these related tutorials:
➡ Python Lists Explained
➡ Python Interactive Tutorial: From Basics to Mastery
➡ Python Tutorial: Mastering Fuzzy Buzzy (FizzBuzz)

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