Automate the Boring Stuff with Python

Chapter 7. Pattern Matching with Regular Expressions

You may be familiar with searching for text by pressing CTRL-F and typing in the words you’re looking for. Regular expressions go one step further: They allow you to specify a pattern of text to search for. You may not know a business’s exact phone number, but if you live in the United States or Canada, you know it will be three digits, followed by a hyphen, and then four more digits (and optionally, a three-digit area code at the start). This is how you, as a human, know a phone number when you see it: 415-555-1234 is a phone number, but 4,155,551,234 is not.

Regular expressions are helpful, but not many non-programmers know about them even though most modern text editors and word processors, ...