GaussianCopula: ValueError: not enough values to unpack (expected 2, got 1)

[csala]

• SDV version: 0.4.5

Description

If an invalid distribution name is passed to GaussianCopula, it crashes with an unclear message.

To fix this, all the inputted distribution names should be validated to ensure that they are valid and raise a user-friendly message if they are not.

What I Did

In [7]: from sdv.demo import load_tabular_demo                                                                                                                                                                                                                                 

In [8]: data = load_tabular_demo()                                                                                                                                                                                                                                             

In [11]: model = GaussianCopula(distribution={'age': 'invalid_distribution_name'})                                                                                                                                                                                                               

In [12]: model.fit(data)                                                                                                                                                                                                                                                       
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-12-bcfd88bde046> in <module>
...
~/.virtualenvs/SDV.clean/lib/python3.6/site-packages/copulas/__init__.py in get_instance(obj, **kwargs)
     51     instance = None
     52     if isinstance(obj, str):
---> 53         package, name = obj.rsplit('.', 1)
     54         instance = getattr(importlib.import_module(package), name)(**kwargs)
     55 

ValueError: not enough values to unpack (expected 2, got 1)

[csala]

This was fixed as part of #251