Terms
Last updated 14 November 2026.
What these terms cover
Buying a book on this website. A book bought in another store, such as Amazon, is sold under that store’s terms and its own refund and delivery rules; the licence printed in the book applies either way.
What you buy
A one-time purchase of a digital book: PDF files, delivered as a download. There is no subscription. The price on the book’s page is what you pay: tax is included, and the checkout shows the same total. Books on sale now: Think in Patterns.
Who sells
Hootshell notebooks are written and sold by Ravi Teja K, who sells under the name ProServIQ, Hyderabad, Telangana, India. Orders are processed by Dodo Payments, the merchant of record: it is the seller on your receipt and handles payment, tax and invoices. Its buyer terms, shown at checkout, apply to the payment.
Your licence
- The book is licensed to the person who bought it, for their own study.
- You may print it and keep copies on your own devices.
- You may not share, resell, upload or post the PDF or any part of it, or use it as material for a course, a dataset or another product.
- You may reuse the Python solutions in your own practice and your own projects.
The full licence is printed in each book (page 5 of Think in Patterns), and it applies wherever you bought the book. Official copies come only from this site and the stores named in the piracy declaration; see also Copyright and DMCA.
Accuracy and corrections
Every Python solution is run against its tests before a release, and we work hard to get every page right. Mistakes found after release are listed on each book’s corrections page and fixed in the next corrected edition, which buyers of the same edition (for example 1.x) get free.
No promise of results
A book can teach a method; it cannot promise a job, an interview or an offer. The practice is yours.
Names of companies and sites
The books are not affiliated with, endorsed by or sponsored by LeetCode or any company named in them. Problem numbers are given only so you can find a problem to practise on, and company names show how widely a problem is reported, not that a company uses it or knows of the book.
Refunds and responsibility
If a book is not for you, the 7-day refund is our promise. Beyond that, the books are provided as they are, and our total responsibility to you is limited to what you paid.
Complaints
Write to Ravi Teja K, our grievance officer, at [email protected]. We acknowledge every complaint within two working days and aim to resolve it within 30 days.
Changes
We may update these terms; the date at the top changes when we do. The terms in place when you bought apply to your purchase.