regular expressions in python introduction regular expression are very powerful way of processing text while looking for recurring patternsthey are often used with data held in plain text files (such as log files)csv files as well as excel files this introduces regular expressionsdiscusses the syntax used to define regular expression pattern and presents the python re module and its use what are regular expressionsa regular expression (also known as regex or even just reis sequence of characters (lettersnumbers and special charactersthat form pattern that can be used to search text to see if that text contains sequences of characters that match the pattern for exampleyou might have pattern defined as three characters followed by three numbers this pattern could be used to look for such pattern in other strings thusthe following strings either match (or containthis pattern or they do notabc aaa matches the pattern does not match the pattern does not match the pattern (cspringer nature switzerland ag huntadvanced guide to python programmingundergraduate topics in computer science