!49708 fix: add command for map file

Merge pull request !49708 from guozhijian/code_docs_map_file_r1.10

docs/api/api_python/mindrecord/mindspore.mindrecord.ImageNetToMR.rst

@@ -4,7 +4,7 @@
     将ImageNet数据集转换为MindRecord格式数据集。
 
     参数：
-        - **map_file** (str) - 标签映射文件的路径。映射文件内容如下：
+        - **map_file** (str) - 标签映射文件的路径。该文件可通过命令： :code:`ls -l [image_dir] | grep -vE "总用量|total|\." | awk -F " " '{print $9, NR-1;}' > [file_path]` 生成，其中 `image_dir` 为ImageNet数据集的目录路径， `file_path` 为生成的 `map_file` 文件 。 `map_file` 文件内容示例如下：
 
           .. code-block::
 

mindspore/python/mindspore/dataset/engine/datasets_standard_format.py

@@ -112,9 +112,9 @@ class MindDataset(MappableDataset, UnionBaseDataset):
     The columns of generated dataset depend on the source MindRecord files.
 
     Args:
-        dataset_files (Union[str, list[str]]): If dataset_file is a str, it represents for
+        dataset_files (Union[str, list[str]]): If `dataset_files` is a str, it represents for
             a file name of one component of a mindrecord source, other files with identical source
-            in the same path will be found and loaded automatically. If dataset_file is a list,
+            in the same path will be found and loaded automatically. If `dataset_files` is a list,
             it represents for a list of dataset files to be read directly.
         columns_list (list[str], optional): List of columns to be read (default=None).
         num_parallel_workers (int, optional): The number of readers (default=None).

mindspore/python/mindspore/mindrecord/tools/imagenet_to_mr.py

@@ -27,11 +27,14 @@ __all__ = ['ImageNetToMR']
 
 
 class ImageNetToMR:
-    """
+    r"""
     A class to transform from imagenet to MindRecord.
 
     Args:
-        map_file (str): The map file that indicates label. The map file content should be like this:
+        map_file (str): The map file that indicates label. This file can be generated by command
+            :code:`ls -l [image_dir] | grep -vE "total|\." | awk -F " " '{print $9, NR-1;}' > [file_path]` ,
+            where `image_dir` is image directory contains n02119789, n02100735, n02110185 and n02096294 directory
+            and `file_path` is the generated `map_file` . An example of `map_file` is as below:
 
             .. code-block::