def __init__(self, key_to_list_mapping):
        for k, v in key_to_list_mapping.items():
            current = self
            bits = k.split('.')
            for bit in bits[:-1]:
                current = current.setdefault(bit, {})
            # Now assign value to current position
            try:
                current[bits[-1]] = v
            except __HOLE__: # Special-case if current isn't a dict.
                current = {bits[-1] : v}
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-0.96/django/utils/datastructures.py/DotExpandedDict.__init__