Book Image

Learn Python Programming, 3rd edition - Third Edition

By : Fabrizio Romano, Heinrich Kruger
5 (1)
Book Image

Learn Python Programming, 3rd edition - Third Edition

5 (1)
By: Fabrizio Romano, Heinrich Kruger

Overview of this book

Learn Python Programming, Third Edition is both a theoretical and practical introduction to Python, an extremely flexible and powerful programming language that can be applied to many disciplines. This book will make learning Python easy and give you a thorough understanding of the language. You'll learn how to write programs, build modern APIs, and work with data by using renowned Python data science libraries. This revised edition covers the latest updates on API management, packaging applications, and testing. There is also broader coverage of context managers and an updated data science chapter. The book empowers you to take ownership of writing your software and become independent in fetching the resources you need. You will have a clear idea of where to go and how to build on what you have learned from the book. Through examples, the book explores a wide range of applications and concludes by building real-world Python projects based on the concepts you have learned.
Table of Contents (18 chapters)
16
Other Books You May Enjoy
17
Index

Decorators

In Chapter 5, Comprehensions and Generators, we measured the execution time of various expressions.

If you recall, we had to initialize a variable to the start time and subtract it from the current time after execution in order to calculate the elapsed time. We also printed it on the console after each measurement. That was tedious.

Every time we find ourselves repeating things, an alarm bell should go off. Can we put that code in a function and avoid repetition? The answer most of the time is yes, so let's look at an example:

# decorators/time.measure.start.py
from time import sleep, time
def f():
    sleep(.3)
def g():
    sleep(.5)
t = time()
f()
print('f took:', time() - t)  # f took: 0.3001396656036377
t = time()
g()
print('g took:', time() - t)  # g took: 0.5039339065551758

In the preceding code, we defined two functions, f() and g(), which do nothing but sleep (for 0.3 and 0.5 seconds, respectively). We used the sleep()...