What is the dominant reason for Python's popularity as a systems and application programming language?

Question

Coming from an enterprise systems background (think Java and Windows) - I'm surprised at the popularity of python as a prototyping language and am trying to put my finger on the precise reason for this. Examples include being listed as one of the four languages Google uses. Possible reasons include:

• enables rapid systems application prototyping using of c++ libraries using swig wrappers
• built to a well defined language specification
• innovative features at the syntax level enabling high level of expressiveness
• highly flexible web frameworks built long before other languages (django)

The questions is what makes it so popular/highly regarded, but to give some balance I'm going to give some reasons it might not be popular:

• less tool support
• less enterprise support (ie a vendor helpdesk)
• lower performance
• BDFL not caring about backward compatibility in version upgrades

Or was it just the best at a particular point in time (about 8 years ago) and other languages and frameworks have since caught up?

Answer 1

1. Highly expressive language. People often say, "Python works the way my brain does".
2. Dynamic typing means you spend zero time appeasing the compiler.
3. A large standard library means you often have the tools you need at your fingertips.
4. An even larger stable of third-party packages (PIL, Numpy, NLTK, Django) mean that large problem domains are often well-supported.
5. Open-source implementation means you don't have to grovel at the vendor helpdesk, you can find answers yourself, and get solutions from a large community of users.