Do not create series sub-directories

eurostat_to_dbnomics.py

@@ -108,7 +108,6 @@ def iter_git_objects_in_sdmx_file(sdmx_file_path, category_tree, dataset_json_st
             elif series_element_name is not None and element.tag == series_element_name and action == "end":
                 # Exit a series.
                 series_element = element
-                series_tree = Tree()
 
                 # Ignore some specific XML element attributes corresponding to series SDMX attributes,
                 # because series SDMX attributes do not exist in DB.nomics.
@@ -171,7 +170,7 @@ def iter_git_objects_in_sdmx_file(sdmx_file_path, category_tree, dataset_json_st
                     json.dumps(series_json, ensure_ascii=False, indent=2, sort_keys=True).encode('utf-8')
                 )
                 yield series_json_blob
-                series_tree.add(b"series.json", git_blob_filemode, series_json_blob.id)
+                dataset_tree.add("{}.json".format(series_code).encode('utf-8'), git_blob_filemode, series_json_blob.id)
 
                 # Write observations.tsv
 
@@ -238,9 +237,8 @@ def iter_git_objects_in_sdmx_file(sdmx_file_path, category_tree, dataset_json_st
 
                 observations_tsv_blob = Blob.from_string(observations_tsv_str.encode('utf-8'))
                 yield observations_tsv_blob
-                series_tree.add(b"observations.tsv", git_blob_filemode, observations_tsv_blob.id)
-                yield series_tree
-                dataset_tree.add(series_code.encode('utf-8'), git_tree_filemode, series_tree.id)
+                dataset_tree.add("{}.tsv".format(series_code).encode('utf-8'),
+                                 git_blob_filemode, observations_tsv_blob.id)
 
                 # From https://stackoverflow.com/questions/12160418/why-is-lxml-etree-iterparse-eating-up-all-my-memory
                 # It's safe to call clear() here because no descendants will be accessed