Talking to the Human 💬

input() asks a question

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

What is your name? Guybrush Threepwood
Nice to meet you, Guybrush Threepwood.

When you press ▶ run here, your browser pops up a box. In a terminal, the program stops and waits for you to type and press Enter. Either way, input() hands back whatever the human typed, and you catch it in a variable.

Note the trailing space in "What is your name? ". Without it, the cursor would sit flush against the question mark and look wrong. Small thing, and people notice.

The trap

Everything input() returns is text. Everything. Always.

age = input("How old are you? ")
print(f"You said: {age}")
print(f"Its type is: {type(age)}")

How old are you? 30
You said: 30
Its type is: <class 'str'>

So this breaks:

age = input("How old are you? ")
print(age + 10)

Traceback (most recent call last):
  File "ages.py", line 2, in <module>
    print(age + 10)
          ~~~~^~~~
TypeError: can only concatenate str (not "int") to str

The fix is to convert, explicitly:

age = int(input("How old are you? "))
print(f"In ten years you will be {age + 10}.")

How old are you? 30
In ten years you will be 40.

What if they type nonsense?

int("banana") raises ValueError and your program stops dead. Level 3 teaches the proper defence (try/except, Lesson 22). Until then, know that this is the correct instinct to be worried about: any program that trusts what a human typed is one typo away from a crash.

raw = input("How many? ")

try:
    count = int(raw)
    print(f"Right, {count} of them.")
except ValueError:
    print(f"'{raw}' is not a number I can use. Try digits only.")

How many? three
'three' is not a number I can use. Try digits only.

Several questions

name = input("Name: ")
ship = input("Ship: ")
crew = int(input("Crew size: "))

print()
print("=" * 34)
print(f"  Captain {name}")
print(f"  Vessel:  {ship}")
print(f"  Crew:    {crew} ({crew * 2} legs)")
print("=" * 34)

Name: Guybrush
Ship: Sea Monkey
Crew size: 12

==================================
  Captain Guybrush
  Vessel:  Sea Monkey
  Crew:    12 (24 legs)
==================================

Two small tricks worth stealing: print() with nothing in it prints an empty line, and "=" * 34 repeats a character to draw a rule. Multiplying text is a Python nicety you will use constantly for quick command-line output.

The other half: printing well

print("no", "newline", "between these", end=" -> ")
print("see?")

print("a", "b", "c", sep=" | ")
print("2026", "08", "17", sep="-")

no newline between these -> see?
a | b | c
2026-08-17

end= replaces the newline that print normally adds, and sep= replaces the space it puts between items. Two keyword arguments, surprisingly handy, and a first look at a Python feature you meet properly in Lesson 18.

name = input("Name: ")
drink = input("Poison of choice: ")

print(f"Welcome to the Scumm Bar, {name.strip().title()}.")
print(f"One {drink.strip().lower()}, coming up.")

Name:   gUYBRUSH
Poison of choice:   GROG
Welcome to the Scumm Bar, Guybrush.
One grog, coming up.

width = float(input("Width: "))
height = float(input("Height: "))

area = width * height
perimeter = 2 * (width + height)

print(f"Area:      {area:.1f}")
print(f"Perimeter: {perimeter:.1f}")

Width: 3.5
Height: 4.2
Area:      14.7
Perimeter: 15.4

a = input("First number: ")
b = input("Second number: ")
print(a + b)

a = int(input("First number: "))
b = int(input("Second number: "))
print(a + b)

First number: 2
Second number: 3
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