At this writing, the best estimate anyone can seem to make of the size of the Python user base is that there are roughly 1 million Python users around the world today (plus or minus a few). This estimate is based on various statistics, like download rates, web statistics, and developer surveys. Because Python is open source, a more exact count is difficult—there are no license registrations to tally. Moreover, Python is automatically included with Linux distributions, Macintosh computers, and a wide range of products and hardware, further clouding the user-base picture.
In general, though, Python enjoys a large user base and a very active developer community. It is generally considered to be in the top 5 or top 10 most widely used programming languages in the world today (its exact ranking varies per source and date). Because Python has been around for over two decades and has been widely used, it is also very stable and robust.
Besides being leveraged by individual users, Python is also being applied in real revenue-generating products by real companies. For instance, among the generally known Python user base:
Google makes extensive use of Python in its web search systems.
The popular YouTube video sharing service is largely written in Python.
The Dropbox storage service codes both its server and desktop client software primarily in Python.
The Raspberry Pi single-board computer promotes Python as its educational language.
EVE Online, a massively multiplayer online game (MMOG) by CCP Games, uses Python broadly.
The widespread BitTorrent peer-to-peer file sharing system began its life as a Python program.
Industrial Light & Magic, Pixar, and others use Python in the production of animated movies.
ESRI uses Python as an end-user customization tool for its popular GIS mapping products.
Google’s App Engine web development framework uses Python as an application language.
The IronPort email server product uses more than 1 million lines of Python code to do its job.
Maya, a powerful integrated 3D modeling and animation system, provides a Python scripting API.
The NSA uses Python for cryptography and intelligence analysis.
iRobot uses Python to develop commercial and military robotic devices.
The Civilization IV game’s customizable scripted events are written entirely in Python.
The One Laptop Per Child (OLPC) project built its user interface and activity model in Python.
Netflix and Yelp have both documented the role of Python in their software infrastructures.
Intel, Cisco, Hewlett-Packard, Seagate, Qualcomm, and IBM use Python for hardware testing.
JPMorgan Chase, UBS, Getco, and Citadel apply Python to financial market forecasting.
NASA, Los Alamos, Fermilab, JPL, and others use Python for scientific programming tasks.
And so on—though this list is representative, a full accounting is beyond this book’s scope, and is almost guaranteed to change over time. For an up-to-date sampling of additional Python users, applications, and software, try the following pages currently at Python’s site and Wikipedia, as well as a search in your favorite web browser:
Success stories: http://www.python.org/about/success
Application domains: http://www.python.org/about/apps
User quotes: http://www.python.org/about/quotes
Wikipedia page: http://en.wikipedia.org/wiki/List_of_Python_software
Probably the only common thread among the companies using Python today is that Python is used all over the map, in terms of application domains. Its general-purpose nature makes it applicable to almost all fields, not just one. In fact, it’s safe to say that virtually every substantial organization writing software is using Python, whether for short-term tactical tasks, such as testing and administration, or for long-term strategic product development. Python has proven to work well in both modes.