add csv format of scalar (#893)

visualdl/server/api.py

@@ -122,10 +122,10 @@ class Api(object):
         key = os.path.join('data/plugin/scalars/scalars', run, tag)
         return self._get_with_retry(key, lib.get_scalar, run, tag)
 
-    @result('text/tab-separated-values')
-    def scalar_data(self, run, tag):
-        key = os.path.join('data/plugin/scalars/data', run, tag)
-        return self._get_with_retry(key, lib.get_scalar_data, run, tag)
+    @result('text/csv')
+    def scalar_data(self, run, tag, type='tsv'):
+        key = os.path.join('data/plugin/scalars/data', run, tag, type)
+        return self._get_with_retry(key, lib.get_scalar_data, run, tag, type)
 
     @result()
     def image_list(self, mode, tag):
@@ -222,7 +222,7 @@ def create_api_call(logdir, model, cache_timeout):
         'pr-curve/tags': (api.pr_curve_tags, []),
         'roc-curve/tags': (api.roc_curve_tags, []),
         'scalar/list': (api.scalar_list, ['run', 'tag']),
-        'scalar/data': (api.scalar_data, ['run', 'tag']),
+        'scalar/data': (api.scalar_data, ['run', 'tag', 'type']),
         'image/list': (api.image_list, ['run', 'tag']),
         'image/image': (api.image_image, ['run', 'tag', 'index']),
         'audio/list': (api.audio_list, ['run', 'tag']),

visualdl/server/lib.py

@@ -125,12 +125,13 @@ def get_scalar(log_reader, run, tag):
     return results
 
 
-def get_scalar_data(log_reader, run, tag):
+def get_scalar_data(log_reader, run, tag, type='tsv'):
     run = log_reader.name2tags[run] if run in log_reader.name2tags else run
     log_reader.load_new_data()
     result = log_reader.get_log_data('scalar', run, tag)
+    delimeter = '\t' if 'tsv' == type else ','
     with io.StringIO() as fp:
-        csv_writer = csv.writer(fp, delimiter='\t')
+        csv_writer = csv.writer(fp, delimiter=delimeter)
         csv_writer.writerow(['id', 'tag', 'timestamp', 'value'])
         csv_writer.writerows(result)
         result = fp.getvalue()