Chapter 12. Parallelism and Performance

In this chapter, we will cover the following recipes:

• Just-in-time compiling with Numba
• Speeding up numerical expressions with Numexpr
• Running multiple threads with the threading module
• Launching multiple tasks with the concurrent.futures module
• Accessing resources asynchronously with the asyncio module
• Distributed processing with execnet
• Profiling memory usage
• Calculating the mean, variance, skewness, and kurtosis on the fly
• Caching with a least recently used cache
• Caching HTTP requests
• Streaming counting with the Count-min sketch
• Harnessing the power of the GPU with OpenCL

Introduction

The ENIAC, built between 1943 and 1946, filled a large room with eighteen thousand tubes and had a 20-bit memory. We have come a long way since then. The growth has been exponential as also predicted by Moore's law. Whether we are dealing with a self-fulfilling prophecy or a fundamental phenomenon is, of course, hard to say. Purportedly, the growth is starting to...