The book describes the basic capabilities of the PyQt library, which allows you to create applications with a graphical interface in Python. Methods of processing signals and events, managing window properties, creating a form using the Qt Designer program, the operation of multithreaded applications, as well as all the main components (buttons, text fields, lists, tables, etc.) and options for their placement inside the window are considered. The book will be useful as a self-tutorial for novice developers. Readers with programming experience can use the book as a reference. The versions described are PyQt 4.8.3 (includes Qt 4.7.1) and Python 3.2.0.