Fix summarizer pyre fix me issues (pytorch#1479)

Summary:

Fixing unresolved pyre fixme issues in corresponding file

Reviewed By: cyrjano

Differential Revision: D67707848

captum/attr/_utils/summarizer.py

@@ -28,6 +28,9 @@ class Summarizer:
     >>>print(summ.summary['mean'])
     """
 
+    _stats: List[Stat]
+    _summary_stats_indicies: List[int]
+
     @log_usage()
     def __init__(self, stats: List[Stat]) -> None:
         r"""
@@ -37,11 +40,9 @@ def __init__(self, stats: List[Stat]) -> None:
         """
         self._summarizers: List[SummarizerSingleTensor] = []
         self._is_inputs_tuple: Optional[bool] = None
-        # pyre-fixme[4]: Attribute must be annotated.
         self._stats, self._summary_stats_indicies = _reorder_stats(stats)
 
-    # pyre-fixme[3]: Return type must be annotated.
-    def _copy_stats(self):
+    def _copy_stats(self) -> List[Stat]:
         import copy
 
         return copy.deepcopy(self._stats)
@@ -125,48 +126,37 @@ def _reorder_stats(stats: List[Stat]) -> Tuple[List[Stat], List[int]]:
     dep_order = [StdDev, Var, MSE, Mean, Count]
 
     # remove dupe stats
-    # pyre-fixme[9]: stats has type `List[Stat]`; used as `Set[Stat]`.
-    stats = set(stats)
+    stats_set = set(stats)
     summary_stats = set(stats)
 
     from collections import defaultdict
 
-    # pyre-fixme[24]: Generic type `type` expects 1 type parameter, use
-    #  `typing.Type[<base type>]` to avoid runtime subscripting errors.
-    stats_by_module: Dict[Type, List[Stat]] = defaultdict(list)
-    for stat in stats:
+    stats_by_module: Dict[Type[Stat], List[Stat]] = defaultdict(list)
+    for stat in stats_set:
         stats_by_module[stat.__class__].append(stat)
 
     # StdDev is an odd case since it is parameterized, thus
     # for each StdDev(order) we must ensure there is an associated Var(order)
     for std_dev in stats_by_module[StdDev]:
         stat_to_add = Var(order=std_dev.order)  # type: ignore
-        # pyre-fixme[16]: `List` has no attribute `add`.
-        stats.add(stat_to_add)
+        stats_set.add(stat_to_add)
         stats_by_module[stat_to_add.__class__].append(stat_to_add)
 
     # For the other modules (deps[1:n-1]): if i exists =>
     # we want to ensure i...n-1 exists
     for i, dep in enumerate(dep_order[1:]):
         if dep in stats_by_module:
-            # pyre-fixme[16]: `List` has no attribute `update`.
-            stats.update([mod() for mod in dep_order[i + 1 :]])
+            stats_set.update([mod() for mod in dep_order[i + 1 :]])
             break
 
     # Step 2: get the correct order
     # NOTE: we are sorting via a given topological order
-    sort_order = {mod: i for i, mod in enumerate(dep_order)}
-    # pyre-fixme[6]: For 1st argument expected `Type[Union[Count, MSE, Mean, StdDev,
-    #  Var]]` but got `Type[Min]`.
+    sort_order: Dict[Type[Stat], int] = {mod: i for i, mod in enumerate(dep_order)}
     sort_order[Min] = -1
-    # pyre-fixme[6]: For 1st argument expected `Type[Union[Count, MSE, Mean, StdDev,
-    #  Var]]` but got `Type[Max]`.
     sort_order[Max] = -1
-    # pyre-fixme[6]: For 1st argument expected `Type[Union[Count, MSE, Mean, StdDev,
-    #  Var]]` but got `Type[Sum]`.
     sort_order[Sum] = -1
 
-    stats = list(stats)
+    stats = list(stats_set)
     stats.sort(key=lambda x: sort_order[x.__class__], reverse=True)
 
     # get the summary stat indices
@@ -185,6 +175,10 @@ class SummarizerSingleTensor:
     If possible use `Summarizer` instead.
     """
 
+    _stats: List[Stat]
+    _stat_to_stat: Dict[Stat, Stat]
+    _summary_stats: List[Stat]
+
     def __init__(self, stats: List[Stat], summary_stats_indices: List[int]) -> None:
         r"""
         Args:
@@ -196,9 +190,7 @@ def __init__(self, stats: List[Stat], summary_stats_indices: List[int]) -> None:
                 does not require any specific order.
         """
         self._stats = stats
-        # pyre-fixme[4]: Attribute must be annotated.
         self._stat_to_stat = {stat: stat for stat in self._stats}
-        # pyre-fixme[4]: Attribute must be annotated.
         self._summary_stats = [stats[i] for i in summary_stats_indices]
 
         for stat in stats: