小编ben*_*hod的帖子

我可以用什么其他方法代替'lambda'

def calculate_fees(self):
    return sum(map(lambda x: x.fee, self.bookings.values()))

def calculate_donations(self):
    return sum(map(lambda x: x.donation, self.bookings.values()))

def __str__(self):
    output = 'Event: {0} {1} {2}\n'.format(self.event_id, self.event_date, self.venue) + \
             'Miles: {0}\n'.format(self.miles) + \
             'Max Places: {0}\n'.format(self.max_places) + \
             'Basic Fee: £{0}'.format(self.basic_fee)

    if self.bookings:
        output += '\nRunners:\n' + \
                  '\n'.join(map(lambda x: '{0} {1}'.format(x.runner_id, x.club_id), self.bookings.values()))
    return output