Input and Output

Using print(), input(), and formatting output with f-strings.

Printing Output

The print() function writes text to the console. You can pass multiple arguments separated by commas:

print("Name:", "Alice")         # Name: Alice
print("Score:", 95, "/ 100")   # Score: 95 / 100

f-Strings (Formatted String Literals)

f-strings (available since Python 3.6) let you embed expressions directly inside strings:

name = "Bob"
age = 30
print(f"My name is {name} and I am {age} years old.")
# My name is Bob and I am 30 years old.

pi = 3.14159
print(f"Pi ≈ {pi:.2f}")   # Pi ≈ 3.14

Reading Input

input() pauses execution and waits for the user to type something. It always returns a string:

user_name = input("Enter your name: ")
print(f"Hello, {user_name}!")

Converting Input to Numbers

Because input() returns a string, you must convert it before doing arithmetic:

age_str = input("Enter your age: ")
age = int(age_str)
print(f"In 10 years you will be {age + 10}.")

Practical Example — Simple Calculator

a = float(input("Enter first number: "))
b = float(input("Enter second number: "))
print(f"Sum: {a + b}")
print(f"Difference: {a - b}")
print(f"Product: {a * b}")
print(f"Quotient: {a / b:.4f}")