Python re(gex)?

Learn Python Regular Expressions step by step from beginner to advanced levels with hundreds of examples and exercises

The book also includes exercises to test your understanding, which is presented together as a single file in this repo — Exercises.md

For solutions to the exercises, see Exercise_solutions.md.

See Version_changes.md to keep track of changes made to the book.

E-book

• You can download the book from any of these links
  • https://leanpub.com/py_regex
    • You might find reduced price using this coupon: https://leanpub.com/py_regex/c/P7erPYAm1386
  • https://gumroad.com/l/py_regex
• You can also get the book as a bundle:
  • Python 201: Intermediate Python + Python re(gex)? from https://leanpub.com/b/python201_and_regex
    • Python 201 is authored by Michael Driscoll
  • Awesome Regex bundle from https://leanpub.com/b/regex or https://gumroad.com/l/regex
  • (Python|Ruby) regex from https://leanpub.com/b/pythonrubyregex
• See https://learnbyexample.github.io/books/ for list of other books

For a preview of the book, see sample chapters

The book can also be viewed as a single markdown file in this repo. See my blogpost on generating pdf from markdown using pandoc if you are interested in the ebook creation process.

Feedback

Please open an issue if you spot any typo/errors.

I'd also highly appreciate your feedback about the book.

Goodreads: https://www.goodreads.com/book/show/47142552-python-re-gex

Twitter: https://twitter.com/learn_byexample

Table of Contents

1. Preface
2. Why is it needed?
3. re introduction
4. Anchors
5. Alternation and Grouping
6. Escaping metacharacters
7. Dot metacharacter and Quantifiers
8. Interlude: Tools for debugging and visualization
9. Working with matched portions
10. Character class
11. Groupings and backreferences
12. Interlude: Common tasks
13. Lookarounds
14. Flags
15. Unicode
16. regex module
17. Gotchas
18. Further Reading

Acknowledgements

• Python documentation — manuals and tutorials
• /r/learnpython/ and /r/regex/ — helpful forums for beginners and experienced programmers alike
• stackoverflow — for getting answers to pertinent questions on Python and regular expressions
• tex.stackexchange — for help on pandoc and tex related questions
• Cover image: draw.io, tree icon by Gopi Doraisamy under Creative Commons Attribution 3.0 Unported and wand icon by roundicons.com
• Warning and Info icons by Amada44 under public domain
• David Cortesi for helpful feedback on both the technical content and grammar issues
• Kye for spotting a typo
• Hugh's email exchanges helped me significantly to improve the presentation of concepts and exercises
• Christopher Patti for reviewing the book, providing feedback and brightening the day with kind words

Special thanks to Al Sweigart, for introducing me to Python with his awesome automatetheboringstuff book and video course.

Contributing

• Open an issue for suggestions, bugs, typos, etc

License

The book is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

The code snippets are licensed under MIT, see LICENSE file