Input and Output

Programs become far more useful when they react to the person using them. The input() function pauses the program, waits for the user to type something and press Enter, and gives back what they typed as a string.

name = input("What is your name? ")
print("Nice to meet you,", name)

A sample run looks like this (the user typed Riya):

What is your name? Riya
Nice to meet you, Riya

age = int(input("Your age: "))
print("Next year you will be", age + 1)

Controlling print()

print() has two useful options. sep sets what goes between values, and end sets what goes at the end instead of a new line.

print("2026", "10", "25", sep="-")
print("Loading", end="")
print("...", end="")
print(" done")

2026-10-25
Loading... done

Formatting numbers

Inside an f-string you can add a format after a colon. This is the easiest way to line up tables and control decimals.

item = "Pen"
price = 12.5
qty = 4

print(f"{item:<8}|{qty:>4}|{price * qty:>8.2f}")
print(f"{'Total':<8}|{'':>4}|{50:>8.2f}")
print(f"Progress: {0.756:.1%}")
print(f"Big number: {1234567:,}")

Pen     |   4|   50.00
Total   |    |   50.00
Progress: 75.6%
Big number: 1,234,567

• <8 means left-align in 8 characters, >4 means right-align in 4.
• .2f means two decimal places.
• .1% turns a fraction into a percentage.
• , adds thousands separators.