@ victor, I have tried your example but I can not reproduce the leak as you did above. May be am missing something?

I used some other tool and got this summary when I was investigating this:

                            types |   # objects |   total size
================================= | =========== | ============
                      <class 'str |        3916 |    361.40 KB
                     <class 'list |        2513 |    237.41 KB
                     <class 'dict |         197 |    120.28 KB
                     <class 'code |         617 |     86.79 KB
                     <class 'type |          81 |     80.71 KB
                      <class 'int |         497 |     13.60 KB
                    <class 'tuple |         199 |     12.80 KB
              function (__init__) |          61 |      8.10 KB
                  <class 'weakref |          87 |      6.80 KB
        <class 'getset_descriptor |          67 |      4.71 KB
  <class 'collections.OrderedDict |           3 |      4.22 KB
            <class 'enum.EnumMeta |           3 |      2.98 KB
              function (__call__) |          14 |      1.86 KB
                     <class 'cell |          37 |      1.73 KB
                   <enum 'Signals |          32 |      1.62 KB

Am still investigating though.