fixup! Add functionality for setting custom names

src/resdk/resolwe.py

@@ -466,20 +466,16 @@ def _download_files(
         files: List[Union[str, Path]],
         download_dir=None,
         show_progress=True,
-        custom_file_names: Union[List[str], None] = None,
+        custom_file_names: Optional[List[str]] = None,
     ):
         """Download files.
 
         Download files from the Resolwe server to the download
         directory (defaults to the current working directory).
 
         :param files: files to download
-        :type files: list of file URI
         :param download_dir: download directory
-        :type download_dir: string
         :param custom_file_names: list of file names to save the downloaded files as
-        :type custom_file_names: list of strings or None
-        :rtype: None
 
         """
         if not download_dir:
@@ -565,7 +561,7 @@ def _download_files(
                 )
                 if expected_md5 != computed_md5:
                     raise ValueError(
-                        f"Checksum of downloaded file {actual_file_name} does not match the expected value."
+                        f"Checksum ({computed_md5}) of downloaded file {actual_file_name} does not match the expected value of {expected_md5}."
                     )
 
     def data_usage(self, **query_params):

src/resdk/resources/data.py

@@ -325,30 +325,27 @@ def files(self, file_name=None, field_name=None):
         return file_list
 
     def download(
-        self, file_name=None, field_name=None, download_dir=None, custom_file_name=None
+        self,
+        file_name: Optional[str] = None,
+        field_name: Optional[str] = None,
+        download_dir: Optional[str] = None,
+        custom_file_name: Optional[str] = None,
     ):
         """Download Data object's files and directories.
 
         Download files and directories from the Resolwe server to the
         download directory (defaults to the current working directory).
 
-        :param file_name: name of file or directory
-        :type file_name: string
-        :param field_name: file or directory field name
-        :type field_name: string
-        :param download_dir: download path
-        :type download_dir: string
-        :param custom_file_name: custom file name
-        :type custom_file_name: string
-        :rtype: None
-
         Data objects can contain multiple files and directories. All are
         downloaded by default, but may be filtered by name or output
         field:
 
         * re.data.get(42).download(file_name='alignment7.bam')
         * re.data.get(42).download(field_name='bam')
 
+        If custom_file_name is provided, the file will be saved with that name,
+        provided that either field_name or file_name is also specified.
+
         """
         if file_name and field_name:
             raise ValueError("Only one of file_name or field_name may be given.")