Dictionaries

Dictionary key-value pairs store karta hai — kisi cheez ko list ki tarah position se dhoondhne ke bajaye, aap use ek naam se dhoondte ho jo aapne khud choose kiya. Yeh Python ka version hai jise doosri languages hash map ya associative array kehti hain.

person = {"name": "Alice", "age": 30, "city": "NYC"}
print(person)
print(person["name"])

person["age"] = 31
print(person)

person["email"] = "alice@example.com"
print(person)

print(person.keys())
print(person.values())

{'name': 'Alice', 'age': 30, 'city': 'NYC'}
Alice
{'name': 'Alice', 'age': 31, 'city': 'NYC'}
{'name': 'Alice', 'age': 31, 'city': 'NYC', 'email': 'alice@example.com'}
dict_keys(['name', 'age', 'city', 'email'])
dict_values(['Alice', 31, 'NYC', 'alice@example.com'])

• person["name"] "name" key ke andar stored value ko padhta hai
• Existing key ko assign karne se uski value update hoti hai; nayi key ko assign karne se woh add ho jaati hai — dono ke liye same syntax use hota hai
• .keys() aur .values() aapko har key ya har value deti hain, insertion order mein

Aage: sets — ek collection jo duplicates ko automatically hata deta hai aur real mathematical set operations support karta hai.