[Sqlalchemy-tickets] Issue #3005: _determine_joins raises TypeError: 'dict_values' object does not support indexing (zzzeek/sqlalchemy)

[Marek B. <iss...@bi...>]

New issue 3005: _determine_joins raises TypeError: 'dict_values' object does not support indexing
https://bitbucket.org/zzzeek/sqlalchemy/issue/3005/_determine_joins-raises-typeerror

Marek Baczyński:

Python 3.4.0, sqlalchemy master

When using sadisplay (https://pypi.python.org/pypi/sadisplay) like this:


```
#!python

desc = sadisplay.describe(getattr(db, attr) for attr in dir(db))
```

I get an exception:


```
#!
  File "...venv\lib\site-packages\sadisplay\describe.py", line 100, in describe
    mapper = class_mapper(item)
  File "...venv\lib\site-packages\sqlalchemy\orm\base.py", line 378, in class_mapper
    mapper = _inspect_mapped_class(class_, configure=configure)
  File "...venv\lib\site-packages\sqlalchemy\orm\base.py", line 355, in _inspect_mapped_class
    mapper._configure_all()
  File "...venv\lib\site-packages\sqlalchemy\orm\mapper.py", line 1129, in _configure_all
    configure_mappers()
  File "...venv\lib\site-packages\sqlalchemy\orm\mapper.py", line 2544, in configure_mappers
    mapper._post_configure_properties()
  File "...venv\lib\site-packages\sqlalchemy\orm\mapper.py", line 1657, in _post_configure_properties
    prop.init()
  File "...venv\lib\site-packages\sqlalchemy\orm\interfaces.py", line 143, in init
    self.do_init()
  File "...venv\lib\site-packages\sqlalchemy\orm\relationships.py", line 1510, in do_init
    self._setup_join_conditions()
  File "...venv\lib\site-packages\sqlalchemy\orm\relationships.py", line 1586, in _setup_join_conditions
    can_be_synced_fn=self._columns_are_mapped
  File "...venv\lib\site-packages\sqlalchemy\orm\relationships.py", line 1849, in __init__
    self._determine_joins()
  File "...venv\lib\site-packages\sqlalchemy\orm\relationships.py", line 1932, in _determine_joins
    consider_as_foreign_keys=consider_as_foreign_keys
  File "<string>", line 2, in join_condition
  File "...venv\lib\site-packages\sqlalchemy\sql\selectable.py", line 764, in _join_condition
    crit = [(x == y) for x, y in constraints.values()[0]]
TypeError: 'dict_values' object does not support indexing

```

This used to work a couple of days ago with sqlalchemy master.