Cleanup exception handling

Cleanup the code so that it only has a single catch for
UnicodeDecodeError

Author: pedroreys

Diff for: pandas/io/pickle.py

@@ -171,25 +171,22 @@ def read_pickle(
 
     # 1) try standard library Pickle
     # 2) try pickle_compat (older pandas version) to handle subclass changes
-
-    excs_to_catch = (AttributeError, ImportError, ModuleNotFoundError)
+    # 3) try pickle_compat with latin-1 encoding upon a UnicodeDecodeError
 
     try:
-        with warnings.catch_warnings(record=True):
-            # We want to silence any warnings about, e.g. moved modules.
-            warnings.simplefilter("ignore", Warning)
-            return pickle.load(f)
-    except excs_to_catch:
-        # e.g.
-        #  "No module named 'pandas.core.sparse.series'"
-        #  "Can't get attribute '__nat_unpickle' on <module 'pandas._libs.tslib"
+        excs_to_catch = (AttributeError, ImportError, ModuleNotFoundError)
         try:
+            with warnings.catch_warnings(record=True):
+                # We want to silence any warnings about, e.g. moved modules.
+                warnings.simplefilter("ignore", Warning)
+                return pickle.load(f)
+        except excs_to_catch:
+            # e.g.
+            #  "No module named 'pandas.core.sparse.series'"
+            #  "Can't get attribute '__nat_unpickle' on <module 'pandas._libs.tslib"
             return pc.load(f, encoding=None)
-        except UnicodeDecodeError:
-            # e.g. can occur for files written in py27; see GH#28645 and GH#31988
-            return pc.load(f, encoding="latin-1")
     except UnicodeDecodeError:
-        # e.g. can occur for files written in py27; see GH#28645
+        # e.g. can occur for files written in py27; see GH#28645 and GH#31988
         return pc.load(f, encoding="latin-1")
     finally:
         f.close()