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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 _calc_preview_ypos(self):
        "Calculates the previews positions on canvas"

        y = 10
        min_y = [y]
        for k, p in self.previews.items():
            y += p.height() + self.padding
            min_y.append(y)
        return min_y