Book Image

Advanced Python Programming

By : Dr. Gabriele Lanaro, Quan Nguyen, Sakis Kasampalis
Book Image

Advanced Python Programming

By: Dr. Gabriele Lanaro, Quan Nguyen, Sakis Kasampalis

Overview of this book

This Learning Path shows you how to leverage the power of both native and third-party Python libraries for building robust and responsive applications. You will learn about profilers and reactive programming, concurrency and parallelism, as well as tools for making your apps quick and efficient. You will discover how to write code for parallel architectures using TensorFlow and Theano, and use a cluster of computers for large-scale computations using technologies such as Dask and PySpark. With the knowledge of how Python design patterns work, you will be able to clone objects, secure interfaces, dynamically choose algorithms, and accomplish much more in high performance computing. By the end of this Learning Path, you will have the skills and confidence to build engaging models that quickly offer efficient solutions to your problems. This Learning Path includes content from the following Packt products: • Python High Performance - Second Edition by Gabriele Lanaro • Mastering Concurrency in Python by Quan Nguyen • Mastering Python Design Patterns by Sakis Kasampalis
Table of Contents (41 chapters)
Title Page
Copyright
About Packt
Contributors
Preface
Index

Simulating race conditions in Python


Before we discuss a solution that we can implement to solve the problem of race conditions, let's try to simulate the problem in Python. If you have already downloaded the code for this book from the GitHub page, go ahead and navigate to the Chapter21 folder. Let's take a look at the Chapter21/example1.py file—specifically, the update() function, as follows:

# Chapter21/example1.py

import random
import time

def update():
    global counter

    current_counter = counter # reading in shared resource
    time.sleep(random.randint(0, 1)) # simulating heavy calculations
    counter = current_counter + 1 # updating shared resource

The goal of the preceding update() function is to increment a global variable called counter, and it is to be called by a separate thread in our script. Inside the function, we are interacting with a shared resource—in this case, counter. We then assign the value of counter to another local variable, called current_counter (this...