Lesson — Loops
GINNA
RANGE SE.
Fixed baar repeat? for ke saath range() lagao. Start, stop, step — teeno control tumhare haath me.
WHY: ginti loop me
5 overs ka score, 10 students ki attendance, 100 tak ke table — jab kaam fixed baar repeat ho to for ke saath range() lagao. MNC interviews me loop wale questions range se hi start hote hain.
for over in range(1, 6):
print("Over", over, "shuru")
print(list(range(3))) # [0, 1, 2]0 se n-1 tak: range(5) — 5 baar loop.
a se b-1 tak: range(2, 10).
Step ke saath: range(0, 100, 10) — 0, 10, 20...
HOW: start, stop, step
range() list nahi banata — sequence yaad rakhta hai, isliye range(1000000) bhi halka hai. List chahiye to list(range(5)) karo. Peeche chalna ho to negative step: range(5, 0, -1).
for i in range(5, 0, -1):
print(i) # 5 4 3 2 1
print(len(range(10))) # 10Quick check
list(range(3)) ka output kya hoga?
Range 0 se start hota hai aur last number se ek pehle rukta hai.
range(1000000) memory me 10 lakh number nahi rakhta — zaroorat par ek-ek deta hai. Yehi lazy thinking Python ko fast rakhti hai.print(sum(range(101))) # 0..100 ka jod = 5050
print(list(range(5, 0, -1))) # [5, 4, 3, 2, 1]MNC tip: range vs list memory — ek line ka jawab, bade marks.
Common mistakes
range(5)me 5 include nahi hota — 0 se 4 tak.range(1, 10)me 10 include nahi hota.- Step zero rakhna (
range(0, 5, 0)) error dega.
Ab code ko reusable banao — functions seekho.