{'fraction_non_alphanumeric': 0.024870466321243522, 'fraction_numerical': 0.0062176165803108805, 'mean_word_length': 4.819277108433735, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 1, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
FLOP, a free laboratory of programming

The Test Driven Design (TDD) methodology [4, 23, 8] is currently a very common approach for programming and software engineering learning. On-line judges are widely used in everyday teaching, and their use in the scope of programming contests is currently especially well known. There are good tools and collections of programming problems available for exams as well as for contests.
 We have developed a simple, light, and practical open laboratory. The term open is used here in two senses: It is free for students to use and free to download and distribute under the GPL license. This laboratory hosts programming problems, it allows the instructor to easily add new ones, and it also automatically assesses the solutions sent by the students. In addition to the system, we have developed a collection of programming problems for CS1/2, designed from a pedagogical point of view and covering several levels of difficulty.