fix dataset para validator check

mindspore/dataset/engine/samplers.py

@@ -127,7 +127,6 @@ class RandomSampler():
 
     Raises:
         ValueError: If replacement is not boolean.
-        ValueError: If num_samples is not None and replacement is false.
         ValueError: If num_samples is not positive.
      """
 

mindspore/dataset/engine/validators.py

@@ -556,6 +556,11 @@ def check_generatordataset(method):
         if column_names is None:
             raise ValueError("column_names is not provided.")
 
+        # check prefetch_size range
+        prefetch_size = param_dict.get('prefetch_size')
+        if prefetch_size is not None and (prefetch_size <= 0 or prefetch_size > 1024):
+            raise ValueError("prefetch_size exceeds the boundary.")
+
         check_param_type(nreq_param_int, param_dict, int)
 
         check_param_type(nreq_param_list, param_dict, list)

mindspore/dataset/transforms/vision/validators.py

@@ -104,6 +104,10 @@ def check_padding(padding):
             raise ValueError("The size of the padding list or tuple should be 2 or 4.")
     else:
         raise TypeError("Padding can be any of: a number, a tuple or list of size 2 or 4.")
+    if not (isinstance(left, int) and isinstance(top, int) and isinstance(right, int) and isinstance(bottom, int)):
+        raise TypeError("Padding value should be integer.")
+    if left < 0 or top < 0 or right < 0 or bottom < 0:
+        raise ValueError("Padding value could not be negative.")
     return left, top, right, bottom