The first time you write input(), your program appears to hang. Nothing prints. Nothing happens. It looks broken.
It is not. It is waiting for you.
What input() actually does
name = input("What is your name? ")
print("Vanakkam, " + name + "!")
Line by line:
- Python prints the prompt
What is your name? - Python pauses the entire program and waits for you to type something and press Enter
- Whatever you typed becomes a string, stored in
name - Only then does line 2 run
That pause is the point. Your program is not stuck; it is holding the door open.
Bug 1: input() always gives you text
This is the single most common beginner bug:
age = input("Your age: ")
print(age + 1) # TypeError!
Even if you type 20, age is the string "20", not the number 20. And you cannot add a number to a string.
The fix is to convert it:
age = int(input("Your age: "))
print(age + 1) # 21
Read that inner-to-outer: input() collects text, int() turns that text into a whole number.
For decimals, use float():
price = float(input("Price: "))
Bug 2: crashing when the user types something unexpected
age = int(input("Your age: "))
Type twenty and your program dies with ValueError: invalid literal for int(). Guard it:
raw = input("Your age: ")
if raw.isdigit():
age = int(raw)
print("Next year you will be", age + 1)
else:
print("Please type a number, like 20.")
Bug 3: forgetting the space in your prompt
name = input("Your name?")
The cursor sits jammed against the question mark. Add a trailing space — input("Your name? ") — and it looks intentional. Small thing; makes your programs feel finished.
Putting it together
name = input("What is your name? ")
age = int(input("How old are you? "))
years_to_100 = 100 - age
print(f"Hi {name}! You will turn 100 in {years_to_100} years.")
That f before the quotes is an f-string. Anything inside {} gets replaced by its value. It is far easier to read than gluing strings together with +.
Try it yourself
Reading about input() teaches you very little; using it teaches you quickly. The Python course on Beginner Codes runs real Python in your browser, and input() genuinely pauses and waits for you — exactly as it does on your own machine.
Build the classic first program: ask for two numbers, print the sum. Then break it on purpose by typing a word instead of a number, so you recognise that error when it appears in something you actually care about.