Bug report

Memory leak in warnings module
Steps to reproduce:

1. Create test script
   `$ cat > memory_leak_warnings.py << EOF
   import warnings
   import random

while True:
warn_text = str(random.random())
warnings.warn(warn_text, DeprecationWarning)
EOF`

2. Run script
   docker run -it --rm --name memory-leak-warnings -v "$PWD":/usr/src/myapp -w /usr/src/myapp python:3.9 python memory_leak_warnings.py

3. Monitor memory usage of container with running script
   $ docker stats memory-leak-warnings

And you can see MEM USAGE constantly increased

https://docs.python.org/3/library/warnings.html
Warnings is a standard module, anyone can use it.
Having an application with a lot of dependencies - you have no idea which module use warnings module, so in production you will have memory leak.
For example aiomysql use it https://github.com/aio-libs/aiomysql/blob/master/aiomysql/cursors.py#L479 and seems like it is ok to use warnings standard module.

I have to disable warnings to get rid such kind of memory leaks. Is it ok? Or maybe warnings must be disabled on production enviroments? If so - this should be noticed in documentaion.

Thanks

Your environment

• CPython versions tested on: 3.6, 3.7, 3.9, 3.10
• Operating system and architecture: https://hub.docker.com/_/python