added class KeepRefs to get access on object references

timeseriesviewer/utils.py

+
+
+from collections import defaultdict
+import weakref
+class KeepRefs(object):
+    __refs__ = defaultdict(list)
+    def __init__(self):
+        self.__refs__[self.__class__].append(weakref.ref(self))
+
+    @classmethod
+    def instances(cls):
+        for inst_ref in cls.__refs__[cls]:
+            inst = inst_ref()
+            if inst is not None:
+                yield inst
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