Book Image

IPython Interactive Computing and Visualization Cookbook - Second Edition

By : Cyrille Rossant
Book Image

IPython Interactive Computing and Visualization Cookbook - Second Edition

By: Cyrille Rossant

Overview of this book

Python is one of the leading open source platforms for data science and numerical computing. IPython and the associated Jupyter Notebook offer efficient interfaces to Python for data analysis and interactive visualization, and they constitute an ideal gateway to the platform. IPython Interactive Computing and Visualization Cookbook, Second Edition contains many ready-to-use, focused recipes for high-performance scientific computing and data analysis, from the latest IPython/Jupyter features to the most advanced tricks, to help you write better and faster code. You will apply these state-of-the-art methods to various real-world examples, illustrating topics in applied mathematics, scientific modeling, and machine learning. The first part of the book covers programming techniques: code quality and reproducibility, code optimization, high-performance computing through just-in-time compilation, parallel computing, and graphics card programming. The second part tackles data science, statistics, machine learning, signal and image processing, dynamical systems, and pure and applied mathematics.
Table of Contents (19 chapters)
IPython Interactive Computing and Visualization CookbookSecond Edition
Contributors
Preface
Index

Resolving dependencies in a directed acyclic graph with a topological sort


In this recipe, we will show an application of a well-known graph algorithm: topological sorting. Let's consider a directed graph describing dependencies between items. For example, in a package manager, before we can install a given package P, we may need to install dependent packages.

The set of dependencies forms a directed graph. With topological sorting, the package manager can resolve the dependencies and find the right installation order of the packages.

Topological sorting has many other applications. Here, we will illustrate this notion on real data from the JavaScript package manager npm. We will find the installation order of the required packages for the react JavaScript package.

How to do it...

  1. We import a few packages:

    >>> import io
        import json
        import requests
        import numpy as np
        import networkx as nx
        import matplotlib.pyplot as plt
        %matplotlib inline
  2. We download the dataset...