corrections to set label using the standard flags feature

optional: returing self in View.set_flags allowing compact list comprehension for setting labels

Author: Johannes Otepka

docs/source/examples/basic_task_label.py

@@ -21,10 +21,10 @@ def wait(t):
 # use load balanced view
 bview = rc.load_balanced_view()
 ar_list_b1 = [
-    bview.map_async(wait, [2], label=f"mylabel_map_{i:02}") for i in range(10)
+    bview.set_flags(label=f"mylabel_map_{i:02}").map_async(wait, [2]) 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.set_flags(label=f"mylabel_map_{i:02}").apply_async(wait, 2) for i in range(10)
 ]
 bview.wait(ar_list_b1)
 bview.wait(ar_list_b2)
@@ -33,10 +33,12 @@ def wait(t):
 # use direct view
 dview = rc[:]
 ar_list_d1 = [
-    dview.apply_async(wait, 2, label=f"mylabel_map_{i + 10:02}") for i in range(10)
+    dview.set_flags(label=f"mylabel_map_{i + 10:02}").apply_async(wait, 2)
+    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.set_flags(label=f"mylabel_map_{i + 10:02}").map_async(wait, [2])
+    for i in range(10)
 ]
 dview.wait(ar_list_d1)
 dview.wait(ar_list_d2)

ipyparallel/client/view.py

@@ -156,6 +156,8 @@ def set_flags(self, **kwargs):
             else:
                 setattr(self, name, value)
 
+        return self  # returning self would allow direct calling of map/apply in one command (no context manager)
+
     @contextmanager
     def temp_flags(self, **kwargs):
         """temporarily set flags, for use in `with` statements.
@@ -570,12 +572,7 @@ 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
-        )  # this is required can calling apply[_async]
+        label = self.label if label is None else label
         metadata = dict(label=label)
 
         _idents, _targets = self.client._build_targets(targets)
@@ -659,6 +656,8 @@ def map(
 
         if block is None:
             block = self.block
+        if label is None:
+            label = self.label
 
         assert len(sequences) > 0, "must have some sequences to map onto!"
         pf = ParallelFunction(
@@ -1318,6 +1317,8 @@ def set_flags(self, **kwargs):
 
             self.timeout = t
 
+        return self  # returning self would allow direct calling of map/apply in one command (no context manager)
+
     @sync_results
     @save_ids
     def _really_apply(
@@ -1388,12 +1389,7 @@ 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
-        )  # 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]
+        label = self.label if label is None else label
 
         if not isinstance(retries, int):
             raise TypeError(f'retries must be int, not {type(retries)!r}')
@@ -1489,6 +1485,8 @@ def map(
         # default
         if block is None:
             block = self.block
+        if label is None:
+            label = self.label
 
         assert len(sequences) > 0, "must have some sequences to map onto!"