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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def getPercentBlank(self):
        '''Print how many null cells are in the DEM - Quality measure'''
        blank = 0
        nonblank = 0
        for x in self.data.flat:
            if x == -99999.0:
                blank = blank + 1
            else:
                nonblank = nonblank + 1

        print ("Blank tiles =  ", blank, "out of ", (nonblank+blank))