matplotlib.colors.to_rgba_array
- 
matplotlib.colors.to_rgba_array(c, alpha=None)[source] - 
Convert c to a (n, 4) array of RGBA colors.
If alpha is not
None, it forces the alpha value. If c is"none"(case-insensitive) or an empty list, an empty array is returned. If c is a masked array, an ndarray is returned with a (0, 0, 0, 0) row for each masked value or row in c. 
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    https://matplotlib.org/3.1.1/api/_as_gen/matplotlib.colors.to_rgba_array.html