Pythonic array indexing with boolean masking array
Negating a boolean mask array in NumPy is ~mask.
Also, consider whether you actually need where at all. Seemingly the most common use is some_array[np.where(some_mask)], but that's just an unnecessarily wordy and inefficient way to write some_array[some_mask].
I get a PEP8 complaint about numpy.where(mask == False) where mask is a boolean array. The PEP8 recommendation comparison should be either 'if condition is false' or 'if not condition'. What is the pythonic syntax for the suggested comparison inside numpy.where()?