In article <mailman.17862.1421705173.18130.python-l...@python.org>, zacharygilmar...@gmail.com says... > > Why aren't there trees in the python standard library?
I don't know much about python development process and strategies, but I suspect it shouldn't be much different from any other language I know of. So here's my tentative answer: Once general purpose programming languages become established, the STL maintainers tend to greatly decrease additions to the standard library, except when this is required to support new language features. Most of development on the STL shifts to code maintenance in order to improve the quality of the code (usually to address memory usage and performance concerns) and solve any existing bugs on the STL. Instead the language maintainers start to rely on third-party libraries as a continuation of the effort to extend the programming language further. Any new additions to the STL are carefully pondered. The reason is twofold: 1) Just like with the matter of data structures, many additions are implementation-contentious. Trees, for instance, can be implemented in any number of ways, some with an emphasis on performance, others on memory usage. The decision of which implementation to choose isn't easy. And if users can already choose different types of implementations from the external libraries, then this is is probably motivation enough to delay the decision for another day. 2) A standard library should focus first and foremost on support of the language features. If for some reason this takes time away from adding new entries into the STL, that's fine. There's also the problem of how one should look at a standard library. Some maintainers don't look very well at the idea of a monolithic approach, while others, like Guido, like to think of a "batteries- included" programming language, indicating a desire to build a large STL. And this is why perhaps your question arises. But "batteries included" doesn't mean build a "Total Library". That would be a vain attempt for any general purpose language. -- https://mail.python.org/mailman/listinfo/python-list
