Book Image

Modern Python Standard Library Cookbook

By : Alessandro Molina
Book Image

Modern Python Standard Library Cookbook

By: Alessandro Molina

Overview of this book

The Python 3 Standard Library is a vast array of modules that you can use for developing various kinds of applications. It contains an exhaustive list of libraries, and this book will help you choose the best one to address specific programming problems in Python. The Modern Python Standard Library Cookbook begins with recipes on containers and data structures and guides you in performing effective text management in Python. You will find Python recipes for command-line operations, networking, filesystems and directories, and concurrent execution. You will learn about Python security essentials in Python and get to grips with various development tools for debugging, benchmarking, inspection, error reporting, and tracing. The book includes recipes to help you create graphical user interfaces for your application. You will learn to work with multimedia components and perform mathematical operations on date and time. The recipes will also show you how to deploy different searching and sorting algorithms on your data. By the end of the book, you will have acquired the skills needed to write clean code in Python and develop applications that meet your needs.
Table of Contents (21 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Going to tomorrow


When you have a date, it's common to need to apply math to that date. For example maybe you want to move to tomorrow or to yesterday.

Datetimes support math operations, such as adding or subtracting to them, but when time is involved, it's not easy to get the exact number of seconds you need to add or subtract to move to the next or previous day.

For this reason, this recipe will show off an easy way to move to the next or previous day from any given date.

How to do it...

For this recipe, here are the steps:

  1. The shiftdate function will allow us to move to a date by any number of days:
import datetime

def shiftdate(d, days):
    return (
        d.replace(hour=0, minute=0, second=0, microsecond=0) + 
        datetime.timedelta(days=days)
    )
  1. Using it is as simple as just providing the days you want to add or remove:
>>> now = datetime.datetime.utcnow()
>>> now
datetime.datetime(2018, 3, 21, 21, 55, 5, 699400)
  1. We can use it to go to tomorrow:
>>> shiftdate...