A better JSON check_circular

Feature or enhancement

Proposal:

json.dump(check_circular=True) uses a dictionary to track all objects already visited and creates keys with PyLong_FromVoidPtr. There is another solution for recursive container types in CPython already: Py_ReprEnter and Py_ReprLeave.

I have a patch to replace the dictionary and custom object tracking with the CPython functions and that removes some code and also avoids allocating Long objects for each recursive call.

Has this already been discussed elsewhere?

No response given

Links to previous discussion of this feature:

No response

Linked PRs

• gh-137104
• gh-137286

首先检查 json.dump(check_circular=True) 和现有的 Py_ReprEnter/Py_ReprLeave 机制，然后检查关联的 PR gh-137104 和 gh-137286。当所提出的跟踪方法在移除 dictionary 和每次调用的 PyLong_FromVoidPtr allocations 的同时，仍能保留递归容器的行为时，即可视为完成。