Dictionaries

Key/value pairs, iteration, and updates.

01Create and access

main.py

person = {"name": "Ada", "age": 36}
print(person["name"])
print(person.get("city", "Unknown"))

Output

Ada
Unknown

main.py

d = {"a": 1, "b": 2}
d["c"] = 3
d["a"] = 10
print(d)

Output

{'a': 10, 'b': 2, 'c': 3}

main.py

prices = {"apple": 1.2, "bread": 2.5, "milk": 1.0}
for item, price in prices.items():
    print(f"{item}: ${price:.2f}")

Output

apple: $1.20
bread: $2.50
milk: $1.00

main.py

d = {"x": 1, "y": 2, "z": 3}
print(list(d.keys()))
print(list(d.values()))
print(len(d))

Output

['x', 'y', 'z']
[1, 2, 3]
3

main.py

squares = {n: n * n for n in range(1, 6)}
print(squares)

Output

{1: 1, 2: 4, 3: 9, 4: 16, 5: 25}