Functions are defined using the def
keyword followed by the function name, an argument list in parentheses, and a colon to start a new block. Let's quickly define a few functions at the REPL to get the idea:
>>> def square(x): ... return x * x ...
We use the return
keyword to return a value from the function.
As we've seen previously, we call functions by providing the actual arguments in parentheses after the function name:
>>> square(5) 5
Functions aren't required to explicitly return a value though — perhaps they produce side effects:
>>> def launch_missiles(): ... print("Missiles launched!") ... >>> launch_missiles() Missiles launched!
You can return early from a function by using the return
keyword with no parameter:
>>> def even_or_odd(n): ... if n % 2 == 0: ... print("even") ... return ... print("odd") ... >>> even_or_odd(4) even >>> even_or_odd(5) odd
If you don't have an explicit...