You can download your free ebook from O'Reilly.
The Functional Programming in Python by David Mertz - publisher: O'Reilly - released: June 2015.
David Mertz is a director of the Python Software Foundation, and chair
of its Trademarks and Outreach & Education Committees. He wrote the
columns Charming Python and XML Matters for IBM developerWorks and the Addison-Wesley book Text Processing in Python. David has spoken at multiple OSCON and PyCon events.
This is the download link.