I know this should be a classic welcome post but, there is few errors you need to solve before you sleep:
import weakref class Foo(object): pass def callback(x): del lst[:] keepalive =  for i in range(100): lst = [str(i)] foo = Foo() foo.cycle = foo keepalive.append(weakref.ref(foo, callback)) del foo while lst: keepalive.append(lst[:])
As @someone said,
Debugging is twice as hard as writing the code in the first place. Therefore, if we write the code as cleverly as possible, we are, by definition, not smart enough to debug it.
It's very simple to remove this useless article. Just login to your file manager then delete the file from your storage.
Here's some relaxing music in case you're bored: