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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 read_buf(self):
 """Read database file"""


        with open(self.filepath, 'rb') as handler:
            try:
                buf = handler.read()
                
                # There should be a header at least
                if len(buf) < 124:
                    raise KPError('Unexpected file size. It should be more or'
                                  'equal 124 bytes but it is '
                                  '{0}!'.format(len(buf)))
            except:
                raise
        return buf