[PyTorch][Bugfix] Use uint8 instead of bool in pytorch to be compatible with...

[PyTorch][Bugfix] Use uint8 instead of bool in pytorch to be compatible with nightly version (#3406)

* Use uint8 instead of bool in pytorch

* Handle type aliases

* Fix syntax error
Co-authored-by: Jinjing Zhou <VoVAllen@users.noreply.github.com>

python/dgl/backend/__init__.py

@@ -60,9 +60,16 @@ def load_backend(mod_name):
 
             # override data type dict function
             setattr(thismod, 'data_type_dict', data_type_dict)
+
+            # for data types with aliases, treat the first listed type as
+            # the true one
+            rev_data_type_dict = {}
+            for k, v in data_type_dict.items():
+                if not v in rev_data_type_dict.keys():
+                    rev_data_type_dict[v] = k
             setattr(thismod,
                     'reverse_data_type_dict',
-                    {v: k for k, v in data_type_dict.items()})
+                    rev_data_type_dict)
             # log backend name
             setattr(thismod, 'backend_name', mod_name)
         else:

python/dgl/backend/pytorch/tensor.py

@@ -27,7 +27,7 @@ def data_type_dict():
             'int16'   : th.int16,
             'int32'   : th.int32,
             'int64'   : th.int64,
-            'bool'    : th.bool}
+            'bool'    : th.uint8}
 
 def cpu():
     return th.device('cpu')