# -*- coding:utf-8 -*-
import datetime
d1 = datetime.datetime(2018, 3, 21)
d2 = datetime.datetime(2018, 5, 20)
d3 = datetime.datetime(2018, 6, 11)
dd1 = (d2-d1).days
dd2 = (d3-d2).days

# 3月是4户交钱
price1_per_day = 400.0/dd1/4
# 5月是3户交钱
price2_per_day = 300.0/dd2/3

print '3月是4户交钱'
print '5月是3户交钱'
print '实际范围: ~%s ~%s' % (d2.strftime('%Y-%m-%d'), d3.strftime('%Y-%m-%d'))
print '单价/天/户: %.2f' % price1_per_day, '%.2f' % price2_per_day

room_1_d = datetime.datetime(2018, 3, 17)
room_1_fee = price1_per_day * (d2 - room_1_d).days + price2_per_day * (d3 - d2).days

room_2_d = datetime.datetime(2018, 5, 17)
room_2_fee = price2_per_day * (d3 - room_2_d).days

print '补缴费1 %s: %.2f' % (room_1_d.strftime('%Y-%m-%d'), room_1_fee)
print '补缴费2 %s: %.2f' % (room_2_d.strftime('%Y-%m-%d'), room_2_fee)