This app includes a one-time purchase (not a subscription): permanent (forever) access to all comments, as well as turning off ads. The main content (all tasks and examples without comments) of the app is available for free. 1. Examples of solutions of exercises and practice problems in the Python programming language, including known algorithms (binary search, Euclidean algorithm, sieve of Eratosthenes, factorial calculation, Fibonacci series, finding the greatest common divisor and the least common multiple). Some examples contain detailed comments. Sections: linear algorithms, conditions, cycles, strings, lists, dictionaries, functions, files. 2. Examples of using built-in functions of Python and methods of the base classes - strings, lists, dictionaries, sets, file objects. Examples of exception handling, demonstration of the features of object-oriented programming in Python, examples of list comprehension. 3. Demonstration of the base features of a number modules of the Python standard library - datetime, calendar, time, random, os and os.path.