Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying Functional Python Programming
  • Table Of Contents Toc
  • Feedback & Rating feedback
Functional Python Programming

Functional Python Programming

By : Steven F. Lott
4 (9)
close
close
Functional Python Programming

Functional Python Programming

4 (9)
By: Steven F. Lott

Overview of this book

This book is for developers who want to use Python to write programs that lean heavily on functional programming design patterns. You should be comfortable with Python programming, but no knowledge of functional programming paradigms is needed.
Table of Contents (18 chapters)
close
close
17
Index

Group-by reductions – from many to fewer

A very common operation is a reduction that groups values by some key or indicator. In SQL, this is often called the SELECT GROUP BY operation. The raw data is grouped by some columns value and reductions (sometimes aggregate functions) are applied to other columns. The SQL aggregate functions include SUM, COUNT, MAX, and MIN.

The statistical summary called the mode is a count that's grouped by some independent variable. Python offers us several ways to group data before computing a reduction of the grouped values. We'll start by looking at two ways to get simple counts of grouped data. Then we'll look at ways to compute different summaries of grouped data.

We'll use the trip data that we computed in Chapter 4, Working with Collections. This data started as a sequence of latitude-longitude waypoints. We restructured it to create legs represented by three tuples of start, end, and distance for the leg. The data looks as follows...

Unlock full access

Continue reading for free

A Packt free trial gives you instant online access to our library of over 7000 practical eBooks and videos, constantly updated with the latest in tech

Create a Note

Modal Close icon
You need to login to use this feature.
notes
bookmark search playlist font-size

Change the font size

margin-width

Change margin width

day-mode

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Delete Bookmark

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete

Delete Note

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete

Edit Note

Modal Close icon
Write a note (max 255 characters)
Cancel
Update Note

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY