corrections to get map and apply to work for balanced and direct view

Author: Johannes Otepka

docs/source/examples/basic_task_label.py

@@ -20,13 +20,26 @@ def wait(t):
 
 # use load balanced view
 bview = rc.load_balanced_view()
-ar_list1 = [bview.map_async(wait, [2], label=f"mylabel_{i:02}") for i in range(10)]
-bview.wait(ar_list1)
+ar_list_b1 = [
+    bview.map_async(wait, [2], label=f"mylabel_map_{i:02}") for i in range(10)
+]
+ar_list_b2 = [
+    bview.apply_async(wait, 2, label=f"mylabel_apply_{i:02}") for i in range(10)
+]
+bview.wait(ar_list_b1)
+bview.wait(ar_list_b2)
+
 
 # use direct view
 dview = rc[:]
-ar_list2 = [dview.apply_async(wait, 2, label=f"mylabel_{i + 10:02}") for i in range(10)]
-dview.wait(ar_list2)
+ar_list_d1 = [
+    dview.apply_async(wait, 2, label=f"mylabel_map_{i + 10:02}") for i in range(10)
+]
+ar_list_d2 = [
+    dview.map_async(wait, [2], label=f"mylabel_apply_{i + 10:02}") for i in range(10)
+]
+dview.wait(ar_list_d1)
+dview.wait(ar_list_d2)
 
 # query database
 data = rc.db_query({'label': {"$nin": ""}}, keys=['msg_id', 'label', 'engine_uuid'])

ipyparallel/client/view.py

@@ -98,14 +98,15 @@ class View(HasTraits):
     block = Bool(False)
     track = Bool(False)
     targets = Any()
+    label = Any()
 
     history = List()
     outstanding = Set()
     results = Dict()
     client = Instance('ipyparallel.Client', allow_none=True)
 
     _socket = Any()
-    _flag_names = List(['targets', 'block', 'track'])
+    _flag_names = List(['targets', 'block', 'track', 'label'])
     _in_sync_results = Bool(False)
     _targets = Any()
     _idents = Any()
@@ -569,9 +570,12 @@ def _really_apply(
         block = self.block if block is None else block
         track = self.track if track is None else track
         targets = self.targets if targets is None else targets
+        label = (
+            self.label if label is None else label
+        )  # comes into play when calling map[_async] (self.label)
         label = (
             kwargs.pop("label") if "label" in kwargs and label is None else label
-        )  # is this the correct/best way of retieving label?
+        )  # this is required can calling apply[_async]
         metadata = dict(label=label)
 
         _idents, _targets = self.client._build_targets(targets)
@@ -658,7 +662,12 @@ def map(
 
         assert len(sequences) > 0, "must have some sequences to map onto!"
         pf = ParallelFunction(
-            self, f, block=block, track=track, return_exceptions=return_exceptions
+            self,
+            f,
+            block=block,
+            track=track,
+            return_exceptions=return_exceptions,
+            label=label,
         )
         return pf.map(*sequences)
 
@@ -1308,11 +1317,6 @@ def set_flags(self, **kwargs):
                     raise ValueError(f"Invalid timeout: {t}")
 
             self.timeout = t
-        if 'label' in kwargs:
-            l = kwargs['label']
-            if not isinstance(l, (str, type(None))):
-                raise TypeError(f"Invalid type for label: {type(l)!r}")
-            self.label = l
 
     @sync_results
     @save_ids
@@ -1384,7 +1388,12 @@ def _really_apply(
         follow = self.follow if follow is None else follow
         timeout = self.timeout if timeout is None else timeout
         targets = self.targets if targets is None else targets
-        label = self.label if label is None else label
+        label = (
+            self.label if label is None else label
+        )  # comes into play when calling map[_async] (self.label)
+        label = (
+            kwargs.pop("label") if "label" in kwargs and label is None else label
+        )  # this is required can calling apply[_async]
 
         if not isinstance(retries, int):
             raise TypeError(f'retries must be int, not {type(retries)!r}')