Green light: go. Red light: stop. Today Bittu learns IF this, do that — the superpower inside every game, app and robot.
1The IF spell
An if checks a truth test. If it's True, the indented lines run. If not — they're skipped, like a door that stays closed:
🐍
Py: Two sacred rules: end the if line with a : colon, and give the inside lines 4 spaces of indent. That's how Python knows what's "inside" the if.
2if / else — two doors
🚪 else is the other door: what to do when the test is False.
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Bittu: I always walk through exactly ONE door. Test True → first door. Test False → else door. Never both.
3elif — a ladder of doors
Need more than two choices? elif (else-if) makes a ladder. Bittu goes down the ladder and stops at the FIRST True:
The Grade Machine 🎓 — slide the marks!
marks = 65
→ took the elif marks >= 60 door: Great! 🎉
4When Bugly attacks 🐞
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Bugly: My two favourite traps! Forget the colon… or mess up the spaces. Watch:
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Professor Hoot: SyntaxError = grammar mistake. IndentationError = spacing mistake. Both are fixed in seconds once you can READ them — that's a real programmer skill.
5Decisions + truth tests together
Combine Day 3 and Day 4 — the rollercoaster gate, now automated:
6Quick quiz! 🧠
marks = 80. What prints? if marks >= 75: print("A") elif marks >= 60: print("B") else: print("C")
💡 80 passes the FIRST test (>= 75), prints A, and the ladder stops there. elif never even looks.
What is missing? if age >= 10 print("ok")
💡 Every if / elif / else line must end with a colon. Python is strict about its punctuation!
7Your mission 🚀
Mission 1: Ask for a password with input(). If it's your secret word, print "Welcome!", else print "Intruder alert! 🚨".
Mission 2: Ask for marks and print Topper (90+), Great (60+), Pass (35+) or Try again — with an elif ladder.
Mission 3: Break your code on purpose: remove a colon, read the error, fix it. Bugly hates this trick.
You finished all 4 free days! 🏆
Loops, lists, functions, files, APIs and real AI await in Days 5–24 — live classes, recordings, and an instructor who answers your doubts.