Python (programming language) was initially set at 2015 then postponed to 2020 out of concern that a large body of existing code could not easily be forward-ported to Python 3. In January 2017, Google announced work on a Python 2.7 to Go transcompiler to improve performance under concurrent workloads. Python is a multi-paradigm programming language. Object-oriented programming and structured programming are fully supported, and many of its features support functional programming and aspect-oriented programming (including by metaprogramming and metaobjects (magic methods)). Many other paradigms are supported via extensions, including design by contract and logic programming. Python uses dynamic typing, and a combination of
YouTube number of videos, can be downloaded as MP4 files. Numerous third-party web sites, applications and browser plug-ins allow users to download YouTube videos. In February 2009, YouTube announced a test service, allowing some partners to offer video downloads for free or for a fee paid through Google Checkout. In June 2012, Google sent cease and desist letters threatening legal action against several websites offering online download and conversion of YouTube videos. In response, Zamzar removed the ability to download YouTube videos from its site. Users retain copyright of their own work, but have the option to grant certain usage rights