Basics
for & while Loops
range(), Iterating Collections
💡 Python ka for loop C/Java ke for loop se bahut alag feel karta hai — index counter manage karne ke bajaye, "har cheez par ghoomo" ka natural syntax hai, jaise "har kitab ke liye shelf mein, uska naam padho."
Python for loop directly kisi collection (list, string, range) ke har element par iterate karta hai — C-style index-based loop (for(i=0;i<n;i++)) Python mein rare hai, kyunki for x in collection: natural aur readable hai.
range(n) 0 se n-1 tak numbers generate karta hai (jab traditional counting chahiye ho). while loop C/Java jaisa hi hai — condition true tak repeat karta hai.
fruits = ["apple", "banana", "cherry"]
for fruit in fruits: # directly elements par iterate
print(fruit)
for i in range(5): # 0, 1, 2, 3, 4
print(i)
count = 0
while count < 3:
print(count)
count += 1 # Python mein ++ nahi hai — += 1 use karo🔁
Python ka for loop C/Java ke for loop se bahut alag feel karta hai — index counter manage karne ke bajaye, "har cheez par ghoomo" ka natural syntax hai, jaise "har kitab ke liye shelf mein, uska naam padho."
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⚡ झट से Recap
- for x in collection: — direct iteration, index manage nahi karna
- range(n) = counting ke liye traditional loops
- ++ / -- nahi hain — += 1 / -= 1 use karo
इस page में (2 subtopics)
Jab loop mein element ke saath uska index bhi chahiye ho, manually counter maintain karne ke bajaye enumerate() use karo — dono ek saath, clean tuple unpacking ke saath.
fruits = ["apple", "banana", "cherry"]
for index, fruit in enumerate(fruits):
print(f"{index}: {fruit}")
# 0: apple
# 1: banana
# 2: cherryTip: enumerate(fruits, start=1) se numbering 1 se shuru kar sakte ho, 0 se nahi — jab human-readable numbering chahiye (jaise "1. apple") ye handy hai.
break/continue C/Java jaise hi hain. Python ki unique feature: for/while loops ke saath else clause bhi ho sakta hai — ye chalta hai agar loop bina break hue poora complete hua.
for i in range(5):
if i == 10:
break
else:
print("Loop bina break ke complete hua") # ye chalega, kyunki 10 kabhi nahi aayaTip: Loop-else pattern rare hai lekin useful "search" scenarios mein — jaise "agar item nahi mila (break nahi hua), ye message dikhao."