Cosmetic changes in docstring and comments to StagedTaskCollection.

gc3libs/workflow.py

@@ -677,7 +677,7 @@ class StagedTaskCollection(SequentialTaskCollection):
     The sequence stops at the first N such that `stageN` is not defined.
 
     The exit status of the whole sequence is the exit status of the
-    last `Task` instance run.  However, if any of the `stageX` methods
+    last `Task` instance run.  However, if any of the `stageN` methods
     returns an integer value instead of a `Task` instance, then the
     sequence stops and that number is used as the sequence exit
     code.
@@ -692,16 +692,16 @@ def __init__(self, **extra_args):
                 SequentialTaskCollection.__init__(
                     self, [first_stage], **extra_args)
             elif isinstance(first_stage, (int, long, tuple)):
-                # init parent class with no tasks, an dimmediately set the
-                # exitcode
+                # init parent class with no tasks,
+                # and immediately set the exitcode
                 SequentialTaskCollection.__init__(self, [], **extra_args)
                 self.execution.returncode = first_stage
                 self.execution.state = Run.State.TERMINATED
             else:
                 raise AssertionError(
                     "Invalid return value from method `stage0()` of"
                     " `StagedTaskCollection` object %r:"
-                    " must return `Task` instance or number" % self)
+                    " must return `Task` instance or integer exit code" % self)
         except AttributeError as ex:
             raise AssertionError(
                 "Invalid `StagedTaskCollection` instance %r: %s"