Book Image

Functional Python Programming - Second Edition

By : Steven F. Lott
Book Image

Functional Python Programming - Second Edition

By: Steven F. Lott

Overview of this book

If you’re a Python developer who wants to discover how to take the power of functional programming (FP) and bring it into your own programs, then this book is essential for you, even if you know next to nothing about the paradigm. Starting with a general overview of functional concepts, you’ll explore common functional features such as first-class and higher-order functions, pure functions, and more. You’ll see how these are accomplished in Python 3.6 to give you the core foundations you’ll build upon. After that, you’ll discover common functional optimizations for Python to help your apps reach even higher speeds. You’ll learn FP concepts such as lazy evaluation using Python’s generator functions and expressions. Moving forward, you’ll learn to design and implement decorators to create composite functions. You'll also explore data preparation techniques and data exploration in depth, and see how the Python standard library fits the functional programming model. Finally, to top off your journey into the world of functional Python, you’ll at look at the PyMonad project and some larger examples to put everything into perspective.
Table of Contents (22 chapters)
Title Page
Packt Upsell

The HTTP request-response model

The HTTP protocol is nearly stateless: a user agent (or browser) makes a request and the server provides a response. For services that don't involve cookies, a client application can take a functional view of the protocol. We can build a client using the http.client or urllib library. An HTTP user agent essentially executes something similar to the following:

import urllib.request
def urllib_demo(url):
    with urllib.request.urlopen(url) as response:


A program like wget or curl does this kind of processing using a URL supplied as a command-line argument. A browser does this in response to the user pointing and clicking; the URL is taken from the user's actions, often the action of clicking on linked text or images.

The practical considerations of user-experience (UX) design, however, lead to some implementation details that are stateful. When a client is obliged to track...