!979 dataset: repair parameter check in rename Op

Merge pull request !979 from ms_yan/rename_columns

mindspore/ccsrc/dataset/engine/datasetops/rename_op.cc

@@ -51,12 +51,7 @@ Status RenameOp::Builder::Build(std::shared_ptr<RenameOp> *ptr) {
 //  constructor
 RenameOp::RenameOp(const std::vector<std::string> &in_col_names, const std::vector<std::string> &out_col_names,
                    int32_t op_connector_size)
-    : PipelineOp(op_connector_size), in_columns_(in_col_names), out_columns_(out_col_names) {
-  // check input & output sizes
-  if (in_columns_.size() != out_columns_.size()) {
-    MS_LOG(ERROR) << "Rename operator number of in columns != number of out columns.";
-  }
-}
+    : PipelineOp(op_connector_size), in_columns_(in_col_names), out_columns_(out_col_names) {}
 
 // destructor
 RenameOp::~RenameOp() {}

mindspore/dataset/engine/validators.py

@@ -884,6 +884,14 @@ def check_rename(method):
                 raise ValueError("{} is not provided.".format(param_name))
             check_columns(param, param_name)
 
+        input_size, output_size = 1, 1
+        if isinstance(param_dict.get(req_param_columns[0]), list):
+            input_size = len(param_dict.get(req_param_columns[0]))
+        if isinstance(param_dict.get(req_param_columns[1]), list):
+            output_size = len(param_dict.get(req_param_columns[1]))
+        if input_size != output_size:
+            raise ValueError("Number of column in input_columns and output_columns is not equal.")
+
         return method(*args, **kwargs)
 
     return new_method