fix recursive call for apply_to_collection(include_none=False) (#8719)

Author: awaelchli

CHANGELOG.md

@@ -117,6 +117,10 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
     [#8627](https://github.com/PyTorchLightning/pytorch-lightning/pull/8627))
 
 
+- Fixed recursive call for `apply_to_collection(include_none=False)` ([#8719](https://github.com/PyTorchLightning/pytorch-lightning/pull/8719))
+
+
+
 ## [1.4.0] - 2021-07-27
 
 ### Added

pytorch_lightning/utilities/apply_func.py

@@ -101,7 +101,9 @@ def apply_to_collection(
     if isinstance(data, Mapping):
         out = []
         for k, v in data.items():
-            v = apply_to_collection(v, dtype, function, *args, wrong_dtype=wrong_dtype, **kwargs)
+            v = apply_to_collection(
+                v, dtype, function, *args, wrong_dtype=wrong_dtype, include_none=include_none, **kwargs
+            )
             if include_none or v is not None:
                 out.append((k, v))
         return elem_type(OrderedDict(out))
@@ -111,15 +113,25 @@ def apply_to_collection(
     if is_namedtuple or is_sequence:
         out = []
         for d in data:
-            v = apply_to_collection(d, dtype, function, *args, wrong_dtype=wrong_dtype, **kwargs)
+            v = apply_to_collection(
+                d, dtype, function, *args, wrong_dtype=wrong_dtype, include_none=include_none, **kwargs
+            )
             if include_none or v is not None:
                 out.append(v)
         return elem_type(*out) if is_namedtuple else elem_type(out)
 
     if _is_dataclass_instance(data):
         out = {}
         for field in data.__dataclass_fields__:
-            v = apply_to_collection(getattr(data, field), dtype, function, *args, wrong_dtype=wrong_dtype, **kwargs)
+            v = apply_to_collection(
+                getattr(data, field),
+                dtype,
+                function,
+                *args,
+                wrong_dtype=wrong_dtype,
+                include_none=include_none,
+                **kwargs
+            )
             if include_none or v is not None:
                 out[field] = v
         return elem_type(**out)

tests/utilities/test_apply_func.py

@@ -151,17 +151,17 @@ def __init__(self, initial_dict):
 
 
 def test_apply_to_collection_include_none():
-    to_reduce = [1, 2, 3.4, 5.6, 7]
+    to_reduce = [1, 2, 3.4, 5.6, 7, (8, 9.1, {10: 10})]
 
     def fn(x):
         if isinstance(x, float):
             return x
 
     reduced = apply_to_collection(to_reduce, (int, float), fn)
-    assert reduced == [None, None, 3.4, 5.6, None]
+    assert reduced == [None, None, 3.4, 5.6, None, (None, 9.1, {10: None})]
 
     reduced = apply_to_collection(to_reduce, (int, float), fn, include_none=False)
-    assert reduced == [3.4, 5.6]
+    assert reduced == [3.4, 5.6, (9.1, {})]
 
 
 def test_apply_to_collections():