diff options
Diffstat (limited to 'lib/sqlalchemy/mapping/mapper.py')
| -rw-r--r-- | lib/sqlalchemy/mapping/mapper.py | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/lib/sqlalchemy/mapping/mapper.py b/lib/sqlalchemy/mapping/mapper.py index 0f2b4e19f..a9f7df63c 100644 --- a/lib/sqlalchemy/mapping/mapper.py +++ b/lib/sqlalchemy/mapping/mapper.py @@ -58,9 +58,10 @@ class Mapper(object): for ext_class in global_extensions: ext = ext_class().chain(ext) - - for ext_obj in util.to_list(extension): - ext = ext_obj.chain(ext) + + if extension is not None: + for ext_obj in util.to_list(extension): + ext = ext_obj.chain(ext) self.extension = ext |