import numpy as np

def random_idxs(idxs, rnd=None, n_parts=None):

	if rnd is None or isinstance(rnd, int):
		rnd = np.random.RandomState(rnd)
	else:
		assert isinstance(rnd, np.random.RandomState), \
			"'rnd' should be either a random seed or a RandomState instance!"

	n_parts = n_parts or rnd.randint(1, len(idxs))
	res = rnd.choice(idxs, n_parts, replace=False)
	res.sort()
	return res

class attr_dict(dict):
	def __getattr__(self, name):
		if name in self:
			return self[name]
		else:
			return super(attr_dict, self).get(name)

	def __getitem__(self, key):
		res = super(attr_dict, self).__getitem__(key)

		if isinstance(res, dict):
			return attr_dict(res)
		return res

class _MetaInfo(object):
	def __init__(self, **kwargs):
		for name, value in kwargs.items():
			setattr(self, name, value)
		self.structure = []


from .image import asarray, dimensions