Lesson — Foundation
TYPE BADLO,
KAAM NIKALO.
UPI amount, form input, file data — sab text me aata hai. Hisab lagane ke liye use number me badalna padta hai. Ye lesson int(), float() aur str() pakka kar dega.
WHY: input hamesha string hota hai
Form, input(), file ya API se aaya data mostly string hota hai — chahe dikhe number jaisa. Hisab lagane ke liye use pehle number me badlo. Isi conversion ko casting kehte hain.
amount = "499"
print(amount + amount) # 499499 (text jud gaya!)
total = int(amount) + 100
print(total) # 599 (ab hisaab hua)Text ko poora number banao: int("499").
Decimal wala number: float("99.5").
Number ko wapas text banao: str(499) — message banane me kaam aata hai.
HOW: teen function, teen rule
int() decimal text ko seedha nahi leta — int("10.5") error dega. Pehle float("10.5") karo, phir int(). Aur number aur text ko + se jodne se pehle ek type me lao.
price = float("99.5")
print(int(price)) # 99 (decimal kata)
qty = "3"
print(int(qty) * 50) # 150Quick check
String 42 ko integer banane ki valid Python expression likho.
int function use karo, text quotes me rakho.
"499" text hai jab tak tum int() na bolo. Explicit conversion = explicit soch — yehi achhe programmer ki nishani.# Interview one-liner
print(int("499") + 1) # 500
print(str(500) + " rupaye") # 500 rupayeMNC tip: int("10.5") wala trap — confidently explain karo.
Common mistakes
int("10.5")error dega — pehlefloat()use karo."Total: " + 500error dega — number kostr(500)karo.input()hamesha string deta hai — ye bhoolna sabse common bug hai.
Ab numbers ki duniya me gehre utro — int, float aur calculation ke rules.