The Py4MQL library aims at embedding a Python interpreter in a script, expert advisor or custom indicator written as a plugin for the Metatrader Trading platform. Py4MQL is built in C++ on top of the Boost.Python library and supports Python versions from 2.7 to 3.4 on the Windows operating sysgtem. The library targets both major versions of the MQL language, namely mql5 and mql4 for Metatrader builds 600 and higher.