Source code for astropy.nddata.flag_collection

# Licensed under a 3-clause BSD style license - see LICENSE.rst

from collections import OrderedDict

import numpy as np

from astropy.utils.misc import isiterable

__all__ = ['FlagCollection']

[docs]class FlagCollection(OrderedDict): """ The purpose of this class is to provide a dictionary for containing arrays of flags for the `NDData` class. Flags should be stored in Numpy arrays that have the same dimensions as the parent data, so the `FlagCollection` class adds shape checking to an ordered dictionary class. The `FlagCollection` should be initialized like an `~collections.OrderedDict`, but with the addition of a ``shape=`` keyword argument used to pass the NDData shape. """ def __init__(self, *args, **kwargs): if 'shape' in kwargs: self.shape = kwargs.pop('shape') if not isiterable(self.shape): raise ValueError("FlagCollection shape should be " "an iterable object") else: raise Exception("FlagCollection should be initialized with " "the shape of the data") OrderedDict.__init__(self, *args, **kwargs) def __setitem__(self, item, value, **kwargs): if isinstance(value, np.ndarray): if value.shape == self.shape: OrderedDict.__setitem__(self, item, value, **kwargs) else: raise ValueError("flags array shape {} does not match data " "shape {}".format(value.shape, self.shape)) else: raise TypeError("flags should be given as a Numpy array")