লুপ (Loops)

# Loop over a list
pets = ["cat", "dog", "hamster", "parrot"]
for pet in pets:
    print(f"I love my {pet}!")

print()  # blank line

# Loop over a range of numbers
# range(5) gives: 0, 1, 2, 3, 4
for i in range(5):
    print(f"Count: {i}")

print()  # blank line

# range(start, stop, step)
for i in range(2, 11, 2):
    print(i, end=" ")  # Even numbers from 2 to 10

I love my cat!
I love my dog!
I love my hamster!
I love my parrot!

Count: 0
Count: 1
Count: 2
Count: 3
Count: 4

2 4 6 8 10 

# Countdown timer
countdown = 5
while countdown > 0:
    print(f"{countdown}...")
    countdown -= 1
print("Liftoff! 🚀")

print()

# Guessing game logic
import random
secret = random.randint(1, 10)
guess = 0
attempts = 0

while guess != secret:
    guess = random.randint(1, 10)  # simulate guessing
    attempts += 1

print(f"Found {secret} in {attempts} attempts!")

5...
4...
3...
2...
1...
Liftoff! 🚀

Found 7 in 3 attempts!

# break — stop when you find what you need
numbers = [4, 7, 2, 9, 1, 5]
for n in numbers:
    if n == 9:
        print(f"Found 9! Stopping.")
        break
    print(f"Checking {n}...")

print()

# continue — skip odd numbers
for i in range(10):
    if i % 2 != 0:
        continue  # skip odd numbers
    print(i, end=" ")

print("\n")

# enumerate — get index AND value
fruits = ["আম", "জাম", "কাঁঠাল"]
for index, fruit in enumerate(fruits):
    print(f"{index + 1}. {fruit}")

print()

# enumerate with custom start
for rank, fruit in enumerate(fruits, start=1):
    print(f"#{rank}: {fruit}")

Checking 4...
Checking 7...
Checking 2...
Found 9! Stopping.

0 2 4 6 8 

1. আম
2. জাম
3. কাঁঠাল

#1: আম
#2: জাম
#3: কাঁঠাল

# Multiplication table (3×3)
for row in range(1, 4):
    for col in range(1, 4):
        result = row * col
        print(f"{result:4d}", end="")
    print()  # new line after each row

print()

# Finding pairs that sum to 10
numbers = [2, 4, 6, 8, 3, 7]
for i in range(len(numbers)):
    for j in range(i + 1, len(numbers)):
        if numbers[i] + numbers[j] == 10:
            print(f"{numbers[i]} + {numbers[j]} = 10")

   1   2   3
   2   4   6
   3   6   9

2 + 8 = 10
4 + 6 = 10
3 + 7 = 10