Functions & User Input

Define functions with def name():. Use parameters, default values, and return to send results back.

Python Functions

Define functions with def name():. Use parameters, default values, and return to send results back.

Keep functions small and focused on one job.

Real-life example: A function is a coffee machine button — press once, same steps run every time.

Function with return

def greet(name, role="student"):
    return f"Hello {name}, you are a {role}."

print(greet("Meera"))
print(greet("Carlos", "instructor"))

Python User Input

input() reads text from the keyboard. Always returns a string — cast to int/float when needed.

Validate input and handle errors with try/except for robust CLI apps.

Real-life example: input() is a waiter asking your order — you speak, Python writes it down as text.

Safe numeric input

raw = input("Enter your age: ")
try:
    age = int(raw)
    print(f"Next year you will be {age + 1}.")
except ValueError:
    print("Please enter a valid number.")