<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_length(self, y):
 """Get true length of y. Args: y (list):
 padded list. Returns: lens: true length of y. Examples: [1, 2, 3] """

        lens = [self.find_pad_index(row) for row in y]
        return lens