Python resource leak demo

demo.py

def open_ten_files():
    files = [open("/dev/null") for _ in range(10)]
    silly_map1 = {"files": files}
    silly_map2 = {"files": files}
    silly_map1["other_map"] = silly_map2
    silly_map2["other_map"] = silly_map1
    return silly_map1

mylist = []
max_len = 5

for _ in range(1000):
    mylist.append(open_ten_files())
    if len(mylist) > max_len:
        del mylist[0]

output.txt

Traceback (most recent call last):
  File "/tmp/test.py", line 13, in <module>
    mylist.append(open_ten_files())
                  ^^^^^^^^^^^^^^^^
  File "/tmp/test.py", line 2, in open_ten_files
    files = [open("/dev/null") for _ in range(10)]
             ^^^^^^^^^^^^^^^^^
OSError: [Errno 24] Too many open files: '/dev/null'

https://godbolt.org/z/fPa341fMr