CS 1110 Lecture Notes - Lecture 1: Railways Act 1921, Regular Expression, Regular Language
Document Summary
Regular expressions are ways of looking inside strings. Search engine take what you type and see which string seems most like what you type. Looking for one string inside of another: matches strings. S in list >> requires strings to match. But these aren"t very flexible, so we will look at a technique to allow us to do this. Capital letter followed by 2-10 lower- case letters. Templates and wildcards give us a lot more expressivity when describing strings. A way of expressing templates, wildcards, and flexibly describe lots of kinds of string is: regular. Expression: comes from 1960s idea in linguistics called regular language, regular expression is a language, that can express just about anything in wildcards and templates, this will allow us to do a lot of interesting things. Useful to put in between / after objects. Pythex: returns results of what test strings match with your expressions.