Your first program

Every programmer's first program does one thing: it says hello. Yours will too — and you'll run it right here on this page.

Printing

Python has a built-in function called print(). Whatever you put between the brackets, Python writes to the screen.

print("Hello, world!")

Hello, world!

Press Run and watch the output appear. That's a real Python program — three words long, but real.

Printing more than one thing

Give print() several things separated by commas and it prints them all on one line, with spaces between:

print("My name is", "Ayesha")
print("I am", 13, "years old")

My name is Ayesha
I am 13 years old

Notice the second line mixes text and a number. Python doesn't mind — print() takes almost anything.

Text needs quotes. Numbers don't.

Text in Python is called a string, and strings always wear quotes. Numbers go bare:

print("13")   # a string that happens to look like a number
print(13)     # an actual number
print(13 + 2) # numbers can do maths

13
13
15

The first two lines look the same, but they're different things to Python — "13" + 2 would be an error, because Python won't add a number to text. You'll meet this difference again in the variables lesson.

Common mistake

Forgetting a quote or a bracket is the classic first error. Run this and read what Python says:

print("Where does this end?

Python points at the line and tells you the string was never closed. Error messages look scary for about a week — then they become your best debugging tool. Read them; they're usually right.