The textbook includes tasks and exercises of the university course of discrete mathematics, including sections related to the specifics of information and communication technologies. Each chapter provides theoretical information needed to solve problems of different levels of complexity, answers, and in many cases, detailed explanations of solutions. The second edition of the book reflects the trend of increasing interest in discrete mathematics among computer scientists. Unlike the first edition, we now use Python as a programming language. The choice of this language is due to its versatility and rapid growth in popularity in the world. In our opinion, Python is well suited for teaching methods of developing and analyzing algorithms. In the second edition, we kept the structure of the material the same: each chapter consists of a theoretical part containing basic definitions, theorems and typical problem solving schemes, the following are problems for solving in the classroom under the guidance of a teacher or for independent work. The book adds more than 50 new problems with solutions and answers, as well as test questions to each chapter to test knowledge of basic definitions and theoretical facts. In a number of cases, clarifying comments were made in decisions and evidence or noted inaccuracies were corrected. Mastering the material requires knowledge of the basics of mathematical analysis, analytical geometry and linear algebra, and for chapters 9, 12 and 13 also the basic constructions of the Python programming language.