Make arange code logic clearer (#54264)

python/paddle/tensor/creation.py

@@ -1301,12 +1301,14 @@ def arange(start=0, end=None, step=1, dtype=None, name=None):
 
     if dtype is None:
         for val in [start, end, step]:
-            if isinstance(val, Variable) and not val.is_integer():
+            if isinstance(val, Variable):
+                if not val.is_integer():
                     dtype = paddle.get_default_dtype()
                     break
-            elif not isinstance(val, (int, np.integer)) and not isinstance(
-                val, Variable
-            ):
+                else:
+                    dtype = 'int64'
+            else:
+                if not isinstance(val, np.integer) and not isinstance(val, int):
                     dtype = paddle.get_default_dtype()
                     break
                 else: