In the early days of computing, text processing and text pattern matching was a huge challenge. There were no standards or pattern matching characters designed at that time. Matching text patterns in a bulk-sized file was an extremely difficult task at that time. Until in the 1950s, an American mathematician named  Stephen Kleene  invented  Regular Expressions  which entirely revolutionized text processing, pattern matching, and bulk data manipulation. The regular expression meta character called  Kleene Star (*) is named after him.   What is the Python Regular Expression? A Python regular expression is a sequence of meta characters, that defines a search pattern. We use these patterns in a string-searching algorithm to “find” or “find and replace” on strings. They are strings in which “what to match” is defined or written. The term “regular expressions” is frequently shortened to “regex” at some places. In this, we will learn the basi...