How is Python’s List Implemented?

It’s a dynamic array. Practical proof: Indexing takes (of course with extremely small differences (0.0013 µsecs!)) the same time regardless of index: I would be astounded if IronPython or Jython used linked lists – they would ruin the performance of many many widely-used libraries built on the assumption that lists are dynamic arrays

How does str(list) work?

Well you have a total of 4 questions, let us go one by one. 1. Why does str(list) returns how we see list on the console? How does str(list) work? What is str() and __str__()? The str() callable is to return a printable form of the object only! From the docs str(object) does not always attempt to return a string that is acceptable to eval(); its goal is to return a … Read more

Are dictionaries ordered in Python 3.6+?

Are dictionaries ordered in Python 3.6+? They are insertion ordered[1]. As of Python 3.6, for the CPython implementation of Python, dictionaries remember the order of items inserted. This is considered an implementation detail in Python 3.6; you need to use OrderedDict if you want insertion ordering that’s guaranteed across other implementations of Python (and other ordered behavior[1]). As of Python 3.7, this … Read more

How does the @property decorator work in Python?

The property() function returns a special descriptor object: It is this object that has extra methods: These act as decorators too. They return a new property object: that is a copy of the old object, but with one of the functions replaced. Remember, that the @decorator syntax is just syntactic sugar; the syntax: really means the same thing as so foo the function is replaced … Read more

When is del useful in Python?

Firstly, you can del other things besides local variables Both of which should be clearly useful. Secondly, using del on a local variable makes the intent clearer. Compare: to I know in the case of del foo that the intent is to remove the variable from scope. It’s not clear that foo = None is doing that. If somebody just assigned foo … Read more