O'Reilly logo

Python Data Analysis by Ivan Idris

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Decision trees

The if a: else b statement is one of the most common statements in Python programming. By nesting and combining such statements, we can build a so-called decision tree. This is similar to an old-fashioned flowchart, although flowcharts also allow loops. The application of decision trees in machine learning is called decision tree learning. The end nodes of the trees in decision tree learning, also known as leaves, contain the class labels of a classification problem. Each non-leaf node is associated with a Boolean condition involving feature values. The scikit-learn implementation uses Gini impurity and entropy as information metrics. These metrics measure the probability that an item is misclassified (see http://en.wikipedia.org/wiki/Decision_tree_learning ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required