Update _tqdm.py

chengs · Jan 20, 2017 · 64f5e73 · 64f5e73
1 parent 416c662
commit 64f5e73
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/tqdm/_tqdm.py b/tqdm/_tqdm.py
@@ -100,7 +100,9 @@ def run(self):
             # Then monitor!
             cur_t = self._time()
             # Check for each tqdm instance if one is waiting too long to print
-            for instance in self.tqdm_cls._instances:
+            # Note: self.tqdm_cls._instances set is copied to avoid a RuntimeError
+            # if it changes it's size during the for
+            for instance in self.tqdm_cls._instances.copy():
                 # Only if mininterval > 1 (else iterations are just slow)
                 # and last refresh was longer than maxinterval in this instance
                 if instance.miniters > 1 and \