pyC45 is a super light C4.5 decision tree package for python which contains only one file “pyC45.py”. It provides the user a simple and efficient interface to train a C4.5 decision tree and use it to do predictions or classifications. The trained decision tree is saved as an XML file so that it can be read and easily understood. C4.5 is one of the most popular algorithms in Data Mining and Machine Learning as the so called “Big Data Era” is coming. It is developed by 张驰昱 in Tsinghua University, in winter, 2013.