Python Input & Output

Output with print()

print() values ko standard output par display karta hai.

print("Hello, BrounStack!")
print(42)
print(True)

Try print() →

Print multiple values

print() multiple arguments accept karta hai. By default unke beech ek space insert hota hai.

name = "Aman"
age = 21
course = "Python"

print(name, age, course)

Control separator with sep

sep multiple printed values ke beech ka separator control karta hai.

print("2026", "09", "12", sep="-")
print("HTML", "CSS", "JavaScript", sep=" | ")

Default sep=" " hota hai.

Control line ending with end

Normally print() ke end par newline add hoti hai. end se ise change kar sakte ho.

print("Loading", end="...")
print("done")

Output same line par Loading...done hoga.

Escape sequences

Backslash-based escape sequences string ke andar special characters represent kar sakti hain.

print("Line 1\nLine 2")
print("Name:\tAman")
print("He said \"Hello\"")
print("C:\\Users\\Student")

• \n — new line
• \t — tab
• \" — double quote inside double-quoted string
• \\ — literal backslash

Read user input with input()

input() standard input se text read karta hai. Prompt string optional hai.

name = input("Your name: ")
print("Hello,", name)

Try input() with stdin →

input() returns a string

Important beginner rule: input() normally text yani str return karta hai, even if user digits type kare.

age = input("Age: ")
print(age)
print(type(age))

Convert numeric input

Calculation ke liye input ko intended numeric type me explicitly convert karo.

age = int(input("Age: "))
price = float(input("Price: "))

print(age + 1)
print(price * 2)

Formatted output with f-strings

f-strings readable way se variables aur expressions ko string me embed karti hain.

name = "Aman"
score = 92

print(f"{name} scored {score} marks.")
print(f"Next target: {score + 5}")

Try f-strings →

Format numbers

f-string format specifiers numbers ko readable display dene me useful hain.

price = 1999.5
ratio = 0.875
population = 1250000

print(f"₹{price:.2f}")
print(f"{ratio:.1%}")
print(f"{population:,}")

• .2f — two decimal places
• .1% — percentage with one decimal place
• , — thousands separator

Basic alignment preview

course = "Python"
print(f"|{course:<10}|")
print(f"|{course:^10}|")
print(f"|{course:>10}|")

<, ^, > left, center aur right alignment ke liye use kiye ja sakte hain.

Other formatting styles

str.format() aur old % formatting bhi Python codebases me mil sakte hain, but new beginner code me f-strings usually clearer choice hain.

name = "Aman"
print("Hello, {}".format(name))

Understanding stdin in BrounStack Playground

Online runner me interactive typing ke bajay Program input / stdin box use hota hai. Har line sequential input() call ko feed hoti hai.

name = input("Name: ")
age = int(input("Age: "))

print(f"{name} will be {age + 1} next year.")

Example stdin:

Aman
21

Run with two inputs →

Mini console program

item = input("Item: ")
price = float(input("Price: "))
quantity = int(input("Quantity: "))

total = price * quantity
print("-" * 24)
print(f"Item: {item}")
print(f"Quantity: {quantity}")
print(f"Total: ₹{total:.2f}")

print() for simple debugging

Learning ke waqt values inspect karne ke liye print() useful hai.

price = 200
quantity = 3
print("DEBUG:", price, quantity)

total = price * quantity
print(total)

Larger programs me proper debugger/logging tools better hote hain, but beginner experiments me print-debugging useful habit hai.

Common beginner mistakes

• input() result ko number assume karna without conversion.
• String aur integer ko + se directly combine karna.
• Prompt unclear rakhna.
• Formatting ke liye unnecessary string concatenation karna jab f-string clearer ho.
• Currency/percentage output me suitable formatting na use karna.
• Too many print() calls se output cluttered karna.
• end="" use karke accidental missing line breaks create karna.
• Backslash escape sequences bhoolna.
• Invalid numeric input ke possibility ko ignore karna.

Beginner best practices

• User ko clear prompt do.
• Input ko required type me explicitly convert karo.
• Output labels clear rakho.
• Readable output ke liye f-strings prefer karo.
• Money-like display me decimal places format karo, while remembering exact financial arithmetic is a separate concern.
• Playground stdin me one input per line ka flow samjho.
• Program ko input → process → output sections me mentally organize karo.

Chapter checklist

• print() se single aur multiple values show kar sakte ho?
• sep aur end ka use clear hai?
• input() always text return karta hai — ye rule yaad hai?
• Numeric input ko int()/float() se convert kar sakte ho?
• f-string create kar sakte ho?
• Decimal, percentage aur thousands formatting samajh aayi?
• BrounStack stdin box se multiple inputs feed kar sakte ho?

Open practice starter →