Python language basics 66: a practical example of a yield generator in Python

Introduction

In the previous post we continued our investigation of yield generators in Python. In particular we looked at how a yield function could remember the state of its internal variables. We saw how code execution jumps in and out of a yield function as it’s being enumerated.

At this point you may think that yield functions are interesting but what can they be used for? You’ll find a lot of examples on the internet. In this post we’ll look at the following scenario:

Say you’d like to divide an integer, e.g. 20, into equal parts of 3 and distribute any remainder equally across the groups. The result of such an operation would be the following 3 integers:

7,7,6

20 can be divided into 3 equal parts of 6 and we have a remainder of 20 – 6 * 3 = 2. 2 is then added as 1 and 1 to the first two groups of 6. The result is a more or less equal distribution of the start integer.

The following function will perform just that:

```import math

def distribute_integer(total, divider):
if divider == 0:
yield 0
else:
rest = total % divider
result = total / divider

for i in range(0, divider):
if rest > 0:
rest -= 1
yield math.ceil(result)
else:
yield math.floor(result)

groups = distribute_integer(20, 3)
for g in groups:
print(g)
```

This will print 7,7,6 as expected.

Read all Python-related posts on this blog here.

I'm a .NET/Java developer living and working in Stockholm, Sweden.

One Response to Python language basics 66: a practical example of a yield generator in Python

ultimatemindsettoday

A great WordPress.com site

.NET Tips & Tricks

Robin Sedlaczek's Blog

Developer on Microsoft Technologies

HarsH ReaLiTy

A Good Blog is Hard to Find

Softwarearchitektur in der Praxis

Wissenswertes zu Webentwicklung, Domain-Driven Design und Microservices

the software architecture

thoughts, ideas, diagrams,enterprise code, design pattern , solution designs

Technology Talks

on Microsoft technologies, Web, Android and others

Software Engineering

Web development

Disparate Opinions

Various tidbits

chsakell's Blog

Anything around ASP.NET MVC,WEB API, WCF, Entity Framework & AngularJS

Cyber Matters

Bite-size insight on Cyber Security for the not too technical.

Guru N Guns's

OneSolution To dOTnET.

Johnny Zraiby

Measuring programming progress by lines of code is like measuring aircraft building progress by weight.