Check for the existence of input files

def check_inputs(self):
        """ Check for the existence of input files """
        self.inputs = self.expand_filenames(self.inputs)
        result = False
        if len(self.inputs) == 0 or self.files_exist(self.inputs):
            result = True
        else:
            print("Not executing task. Input file(s) do not exist.")
        return result