numpy.ma.MaskedArray.tolist

MaskedArray.tolist(fill_value=None) [source]

Return the data portion of the masked array as a hierarchical Python list.

Data items are converted to the nearest compatible Python type. Masked values are converted to fill_value. If fill_value is None, the corresponding entries in the output list will be None.

Parameters:	fill_value : scalar, optional The value to use for invalid entries. Default is None.
Returns:	result : list The Python list representation of the masked array.

Examples

>>> x = np.ma.array([[1,2,3], [4,5,6], [7,8,9]], mask=[0] + [1,0]*4)
>>> x.tolist()
[[1, None, 3], [None, 5, None], [7, None, 9]]
>>> x.tolist(-999)
[[1, -999, 3], [-999, 5, -999], [7, -999, 9]]