[core] simplification of result interpretation.

bonobo/examples/environment/env_files/get_passed_env_file.py

@@ -8,7 +8,9 @@ def extract():
     test_user_password = os.getenv('TEST_USER_PASSWORD')
     path = os.getenv('PATH')
 
-    return my_secret, test_user_password, path
+    yield my_secret
+    yield test_user_password
+    yield path
 
 
 def load(s: str):

bonobo/examples/environment/env_vars/get_passed_env.py

@@ -8,7 +8,11 @@ def extract():
     env_test_number = os.getenv('ENV_TEST_NUMBER', 'number')
     env_test_string = os.getenv('ENV_TEST_STRING', 'string')
     env_user = os.getenv('USER')
-    return env_test_user, env_test_number, env_test_string, env_user
+
+    yield env_test_user
+    yield env_test_number
+    yield env_test_string
+    yield env_user
 
 
 def load(s: str):

bonobo/execution/node.py

@@ -1,6 +1,7 @@
 import traceback
 from queue import Empty
 from time import sleep
+from types import GeneratorType
 
 from bonobo import settings
 from bonobo.constants import INHERIT_INPUT, NOT_MODIFIED, BEGIN, END
@@ -10,7 +11,6 @@ from bonobo.structs.bags import Bag
 from bonobo.structs.inputs import Input
 from bonobo.util import get_name, iserrorbag, isloopbackbag, isdict, istuple
 from bonobo.util.compat import deprecated_alias
-from bonobo.util.iterators import iter_if_not_sequence
 from bonobo.util.statistics import WithStatistics
 
 
@@ -120,23 +120,21 @@ class NodeExecutionContext(WithStatistics, LoopingExecutionContext):
     def handle_results(self, input_bag, results):
         # self._exec_time += timer.duration
         # Put data onto output channels
-        try:
-            results = iter_if_not_sequence(results)
-        except TypeError:  # not an iterator
-            if results:
-                self.send(_resolve(input_bag, results))
-            else:
-                # case with no result, an execution went through anyway, use for stats.
-                # self._exec_count += 1
-                pass
-        else:
-            while True:  # iterator
+
+        if isinstance(results, GeneratorType):
+            while True:
                 try:
                     result = next(results)
                 except StopIteration:
                     break
                 else:
                     self.send(_resolve(input_bag, result))
+        elif results:
+            self.send(_resolve(input_bag, results))
+        else:
+            # case with no result, an execution went through anyway, use for stats.
+            # self._exec_count += 1
+            pass
 
 
 def _resolve(input_bag, output):

bonobo/util/iterators.py

@@ -37,12 +37,3 @@ def tuplize(generator):
     return tuplized
 
 
-def iter_if_not_sequence(mixed):
-    if isinstance(mixed, (
-        dict,
-        list,
-        str,
-        bytes,
-    )):
-        raise TypeError(type(mixed).__name__)
-    return iter(mixed)

tests/execution/test_node.py

@@ -102,3 +102,26 @@ def test_node_dict_chained():
     assert len(output) == 2
     assert output[0] == {'id': 1, 'name': 'FOO'}
     assert output[1] == {'id': 2, 'name': 'BAR'}
+
+def test_node_tuple():
+    def f():
+        return 'foo', 'bar'
+
+    with BufferingNodeExecutionContext(f) as context:
+        context.write_sync(Bag())
+        output = context.get_buffer()
+
+        assert len(output) == 1
+        assert output[0] == ('foo', 'bar')
+
+    def g():
+        yield 'foo', 'bar'
+        yield 'foo', 'baz'
+
+    with BufferingNodeExecutionContext(g) as context:
+        context.write_sync(Bag())
+        output = context.get_buffer()
+
+        assert len(output) == 2
+        assert output[0] == ('foo', 'bar')
+        assert output[1] == ('foo', 'baz')