.keys() sometimes doesn't work after saving and reloading

[talwrii]

Repro

ipython
Python 2.7.12 (default, Jun 29 2016, 08:18:26)
Type "copyright", "credits" or "license" for more information.

IPython 2.4.1 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.
[TerminalIPythonApp] WARNING | File not found: '/home/tom/.pythonrc.py'

In [1]: import jsondb

In [2]: jsondb.create({}, url='/tmp/test.db')
Out[2]: <jsondb.JsonDB at 0x7f92c07bf1d0>

In [3]: d = _

In [4]: d.keys()
Out[4]: []

In [5]: d['a'] = 1

In [6]: d.keys()
Out[6]: ['a']

In [7]: d.close()

In [8]: d = jsondb.load(url='/tmp/test.db')

In [9]:

In [9]: d.keys()
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
<ipython-input-9-8bc560538296> in <module>()
----> 1 d.keys()

/home/tom/.local/lib/python2.7/site-packages/jsondb/core.pyc in __getattr__(self, name)
     90
     91     def __getattr__(self, name):
---> 92         cls = self.get_datatype()
     93         try:
     94             attr = getattr(cls, name)

/home/tom/.local/lib/python2.7/site-packages/jsondb/core.pyc in get_datatype(self)
    282
    283     def get_datatype(self):
--> 284         return get_datatype_class(self.datatype)
    285
    286     def data(self, update=False):

/home/tom/.local/lib/python2.7/site-packages/jsondb/datatypes.pyc in get_datatype_class(_type)
     47     if _type == NIL:
     48         return None
---> 49     cls = DATA_INITIAL[_type].__class__
     50     return cls
     51

KeyError: None

In [10]: d.items()
Out[10]: [('a', 1)]

[shaung]

Fixed in trunk! Please reopen this issue If it's still broken.