{'fraction_non_alphanumeric': 0.031117397454031116, 'fraction_numerical': 0.0, 'mean_word_length': 5.156521739130435, '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': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
RE-SPaM: Using Regular Expressions for Sequential Pattern Mining in Trajectory Databases

In sequential pattern mining, languages based on regular expressions (RE) were proposed to restrict frequent sequences to the ones that satisfy user-specified constraints. In these languages, REs are applied over items. We propose a much powerful language, based on regular expressions, denoted RE-SPaM, where the basic elements are constraints over the attributes of the items. Expressions in this language may include attributes, functions over attributes, and variables. We present the data model, sketch the syntax and semantics of RE-SPaM, a set of examples, and suggest how it can be used in the mining process.