Presumably so you don’t have to pay for the memory or performance overhead of supporting resizing? Possibly also to more closely match the semantics of the code with what you want to do, to make it easier to catch errors.
I find Pythons core data structures really convenient and easy to use, but sometimes the C++ programmer in me wishes that I had more options available to me (eg, Python has lists and tuples, C++ has double ended linked lists, arrays, tuples, vectors, double ended vectors in the standard library), the idea being that I can choose something that is a very close match to usage patterns.
Having said that, I’ve never actually found it to be a limitation in real Python code and when memory or performance matters enough that these differences start to show, Python is usually no longer the best tool for the job anyway, so it doesn’t really need these things. Still, sometimes I feel like I want them anyway, probably just because I’ve done enough C++ to be used to having them :)
Sure, with third party libraries (that are mostly written in C), you can get whatever you want. I’m just talking part of the language. In C++, the range of data structures are huge if I use third party libraries. For example, EASTL expands the STL containers with intrusive variants and more.
Of course, an argument could be made that looking just at the language (without third party libraries) is unrealistic and useless, and its true. You could also argue that Python libraries are easier to install and use than C++ libraries (which is also true), but when you look at the languages in isolation, Python only has a few basic structures and C++ has multiple ones.
Again, I acknowledge that this is an academic discussion since in real life, I’ve never actually seen it matter and, when it does, libraries like numpy that delegate the work to C exist and are easy to use.
I don't know: if you really need to do some heavyweight maths in C++, you're going to go the CUDA/heavyweight intrinsic way anyway. I don't yet see how STL containers (excuse me for the pun) contain the performance problem at it's limit - but otherwise why would you use C++?
Also, having these specific structures as part of the standard library would make you think that what you're doing is acceptable: thinking about the overhead of a doubly-linked-list when your variable assignment operation requires an access to a Namespace object based on a variation of a HashMap.
Seriously: whenever you need a fast solution, Python doesn't stop you from building something in C++. But trying to make Python into C++ is either an incredibly long shot or just having no idea what Python is actually useful for.
I find Pythons core data structures really convenient and easy to use, but sometimes the C++ programmer in me wishes that I had more options available to me (eg, Python has lists and tuples, C++ has double ended linked lists, arrays, tuples, vectors, double ended vectors in the standard library), the idea being that I can choose something that is a very close match to usage patterns.
Having said that, I’ve never actually found it to be a limitation in real Python code and when memory or performance matters enough that these differences start to show, Python is usually no longer the best tool for the job anyway, so it doesn’t really need these things. Still, sometimes I feel like I want them anyway, probably just because I’ve done enough C++ to be used to having them :)