Python RegEx

A RegEx, or Regular Expression, is a sequence of characters that forms a search pattern. RegEx can be used to check if a string contains the specified search pattern.

Regular Expressions.

import re

When you have imported the re module, you can start using regular expressions:

Search the string to see if it starts with "The" and ends with "Spain": import re txt = "The rain in Spain"

The re module offers a set of functions that allows us to search a string for a match:

Match object if there is a match anywhere in the string split Returns a list where the string has been split at each match sub Replaces one or many matches with a string

Metacharacters are characters with a special meaning:

[]

Try it » \ Signals a special sequence (can also be used to escape special characters) "\d" Try it ». Any character (except newline character) "he..o" Try it » ^

"^hello" Try it » $

"planet$" Try it » *

"he.*o" Try it » +

"he.+o" Try it » ?

"he.?o" Try it »

Try it » |

"falls|stays" Try it » ()