A Concise Introduction to Programming in Python

Chapter 3

Functions

Functions in Python allow you to break a task down into appropriate sub-

tasks. They are one of the powerful tools of abstraction that higher-level pro-

gramming languages provide. Ideally, every function has a single, well-defined

purpose.

Consider this example, which uses the sqrt() function from the math module

to implement hypot(), also in the math module.

Listing 3.1: Hypotenuse

1 # hypot.py

2

3 from math import sqrt

4

5 def myhypot(x, y):

6 return sqrt(x

**

2 + y

**

2)

7

8 def main():

9 a = float(input("a: "))

10 b = float(input("b: "))

11 print("Hypotenuse:", myhypot(a, b))

12

13 main()

Each chapter, as we begin with a new example, type the ...