How can I find a list of open file objects at a snapshot in time?
Consider a few cases where files can be opened without being closed (either via with or f.close()):
import io
import typing
buf = io.StringIO()
buf.write('memory here') # still open
f = open('/tmp/file.tmp', 'w')
f.write('more memory') # still open
def g() -> None:
open('/tmp/file2.tmp', 'w') # unclosed file
g()
def h() -> typing.TextIO:
return open('/tmp/file3.tmp', 'w')
res = h() # open (res.closed is False)
I am aware that the GC will eventually destroy the objects and close the open files on its own. However, I am interested in manually finding which open files may be using system resources at any given time.
One way it seems is to look in __warningregistry__; is this the defacto way to do such discovery, or is there a better route?
>>> g()
>>> __warningregistry__
{'version': 0, ("unclosed file <_io.TextIOWrapper name='/tmp/file2.tmp' mode='w' encoding='UTF-8'>",
<class 'ResourceWarning'>, 2): True}
