Lists

List ek ordered, badli ja sakne wali collection hai — shayad Python mein sab se zyada istemal hone wala data structure. Aap ek hi list mein alag types mix kar sakte hain, lekin amli tor par aksar lists ek hi type ki cheezein rakhti hain.

fruits = ["apple", "banana", "cherry"]
print(fruits)
print(fruits[0])
print(fruits[-1])

fruits.append("date")
print(fruits)

fruits.remove("banana")
print(fruits)

print(len(fruits))

['apple', 'banana', 'cherry']
apple
cherry
['apple', 'banana', 'cherry', 'date']
['apple', 'cherry', 'date']
3

• fruits[0] pehla item deta hai, fruits[-1] aakhri item deta hai — negative indexes end se ginte hain
• .append() list ke end mein ek item add karta hai, in place
• .remove() jo pehla matching item milta hai use hata deta hai
• Lists badli ja sakti hain (mutable) — agle lesson mein dikhne wale tuples ke bar-aks

Sorting

numbers = [5, 3, 1, 4, 2]
numbers.sort()
print(numbers)
numbers.sort(reverse=True)
print(numbers)

[1, 2, 3, 4, 5]
[5, 4, 3, 2, 1]

.sort() list ko in place sort karta hai (original list ko badalta hai aur kuch wapas nahi karta) — reverse=True order ulta kar deta hai. Agar original ko chhue baghair sorted copy chahiye to sorted(numbers) istemal karo.

Aage: tuples — list ka immutable bhai, aur kab asal mein iska istemal karna chahiye.