X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/9cd1bd27bada41cd13fb9813144fe694a67c2d00..3b12ef6b6d7ff6852f6109ab71dbec382322a686:/sdk/python/arvados/collection.py

diff --git a/sdk/python/arvados/collection.py b/sdk/python/arvados/collection.py
index d4f24047d2..77312e4d49 100644
--- a/sdk/python/arvados/collection.py
+++ b/sdk/python/arvados/collection.py
@@ -1085,7 +1085,7 @@ class RichCollectionBase(CollectionBase):
             return self._portable_data_hash
         else:
             stripped = self.portable_manifest_text().encode()
-            return hashlib.md5(stripped).hexdigest() + '+' + str(len(stripped))
+            return '{}+{}'.format(hashlib.md5(stripped).hexdigest(), len(stripped))
 
     @synchronized
     def subscribe(self, callback):