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Python proposal: add immutable (persistent) dictionaries

python.org
17 pointsdikbrouwer5 comments
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This is the kind of ad-hoc PEP proposal that could be completely avoidable if there was a generic modifier or initialization/declaration construction for declaring a variable as constant. So incredibly simple, so incredibly useful that it's hard to believe that it hasn't been accepted yet (it was proposed).

A const declaration only ensures that the variable always points to the same object, not that that object is immutable. For instance in JS:

const foo = {};

foo.bar = 1;

That depends on the language.

Something interesting to note is that Python’s ContextVar (introduced in Python 3.7) is a persistent dictionary.

https://www.python.org/dev/peps/pep-0567/#implementation

Nice I like having persistent structures available. Then I don't have to safeguared against unintended modifications.

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