mimic_import_error_in_ipython

In [13]: sys.modules["yaml"] = None

In [14]: import anyconfig.backends

In [15]: anyconfig.backends.list_types()
Out[15]:
['bson',
 'configobj',
 'ini',
 'json',
 'msgpack',
 'properties',
 'shellvars',
 'toml',
 'xml']
 
In [16]: import yaml
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-18-fc3d1333bd52> in <module>()
----> 1 import yaml

ImportError: No module named yaml

In [17]: del sys.modules["yaml"]

In [18]: import yaml

In [19]: