fix/256(fsspec): size can be None for drive files

Author: shcheklein

pydrive2/fs/spec.py

@@ -449,11 +449,12 @@ def ls(self, path, detail=False):
                     }
                 )
             else:
+                s = item.get("fileSize")
                 contents.append(
                     {
                         "type": "file",
                         "name": item_path,
-                        "size": int(item["fileSize"]),
+                        "size": int(s) if s is not None else s,
                         "checksum": item.get("md5Checksum"),
                     }
                 )
@@ -493,12 +494,12 @@ def find(self, path, detail=False, **kwargs):
                     new_query_ids[item["id"]] = item_path
                     self._cache_path_id(item_path, item["id"])
                     continue
-
+                s = item.get("fileSize")
                 contents.append(
                     {
                         "name": posixpath.join(bucket, item_path),
                         "type": "file",
-                        "size": int(item["fileSize"]),
+                        "size": int(s) if s is not None else s,
                         "checksum": item.get("md5Checksum"),
                     }
                 )