larryhou · February 27, 2018 12:55
diff --git a/mortage.md b/mortage.md
diff --git a/mortage.py b/mortage.py
 #!/usr/bin/env python
 #encoding:utf-8

 import argparse, sys

 def pay_with_equal_amount(data):
    amount = float(data.amount)
    rate = float(data.interest_rate) / 100 / 12
    periods = int(data.years) * 12
    print amount, rate, periods
    
    payment = amount * rate * pow(1 + rate, periods) / (pow(1 + rate, periods) - 1)

    value, digits = amount, 0
    while value >= 1:
        value = value / 10
        digits += 1
    digits += 3

    remain = amount
    interest_sum, principal_sum, payment_sum = (0, 0, 0)
    print '[等额本息方案] 贷款:%s 利率:%s 期限:%s年'%(data.amount, data.interest_rate, data.years)
    print '|期数|月供|月供利息|累计利息|月供本金|累积本金|剩余贷款|结清占比|月供本金占比|累积本金占比|'
    table_format = '|'
    for n in range(10):
        table_format += ':-:|'
    print table_format
    for n in range(periods):
        interest = remain * rate
        principal = payment - interest
        interest_sum += interest
        principal_sum += principal
        payment_sum += payment

        remain = remain * (1 + rate) - payment
        format = '|%%03d|%%9.2f|%%9.2f|%%%d.2f|%%9.2f|%%%d.2f|%%%d.2f|'%(digits, digits, digits)
        print format%(n + 1, payment, interest, interest_sum, principal, principal_sum, remain), \
            '%6.2f%%|'%((1 - remain / amount) * 100), \
            '%6.2f%%|'%(100 * principal / payment), '%6.2f%%|'%(100 * principal_sum / payment_sum)


 def pay_with_equal_principal(data):
    amount = float(data.amount)
    rate = float(data.interest_rate) / 100 / 12
    periods = int(data.years) * 12
    print amount, rate, periods
    
    fixed_payment = amount / periods

    value, digits = amount, 0
    while value >= 1:
        value = value / 10
        digits += 1
    digits += 3

    remain = amount
    interest_sum, principal_sum, payment_sum = (0, 0, 0)
    print '[等额本金方案] 贷款:%s 利率:%s 期限:%s年'%(data.amount, data.interest_rate, data.years)
    print '|期数|月供|月供利息|累计利息|月供本金|累积本金|剩余贷款|结清占比|月供本金占比|累积本金占比|'
    table_format = '|'
    for n in range(10):
        table_format += ':-:|'
    print table_format
    for n in range(periods):
        interest = remain * rate
        payment = fixed_payment + interest
        principal = fixed_payment
        interest_sum += interest
        principal_sum += principal
        payment_sum += payment

        remain -= fixed_payment
        format = '|%%03d|%%9.2f|%%9.2f|%%%d.2f|%%9.2f|%%%d.2f|%%%d.2f|'%(digits, digits, digits)
        print format%(n + 1, payment, interest, interest_sum, principal, principal_sum, remain), \
            '%6.2f%%|'%((1 - remain / amount) * 100), \
            '%6.2f%%|'%(100 * principal / payment), '%6.2f%%|'%(100 * principal_sum / payment_sum)

 def caculate_mortage_rate():
    rate, periods = 4.0, 30 * 12
    print periods
    print '|利率|月供比例|300万|350万|400万|450万|500万|550万|600万|650万|'
    table_format = '|'
    for n in range(10):
        table_format += ':-:|'
    print table_format
    while rate <= 6.4:
        rate_adj = rate / 100 / 12
        precent = rate_adj * pow(1 + rate_adj, periods) / (pow(1 + rate_adj, periods) - 1)
        print '|%3.1f|%6.4f%%|%8.2f|%8.2f|%8.2f|%8.2f|%8.2f|%8.2f|%8.2f|%8.2f|'%(rate, precent * 100, \
            3000000*precent, 3500000*precent,\
            4000000*precent, 4500000*precent,\
            5000000*precent, 5500000*precent,\
            6000000*precent, 6500000*precent)
        rate += 0.1

 def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('-y', '--years', default = 30, required = True, help = 'number of loan years')
    parser.add_argument('-r', '--interest-rate', required = True, help = 'bank loan interest rate')
    parser.add_argument('-n', '--amount', required = True, help = 'total loan amount')
    data = parser.parse_args(sys.argv[1:])
    
    pay_with_equal_amount(data)
    pay_with_equal_principal(data)
    caculate_mortage_rate()

 if __name__ == '__main__':
    main()
	#!/usr/bin/env python
	#encoding:utf-8

	import argparse, sys

	def pay_with_equal_amount(data):
	amount = float(data.amount)
	rate = float(data.interest_rate) / 100 / 12
	periods = int(data.years) * 12
	print amount, rate, periods

	payment = amount * rate * pow(1 + rate, periods) / (pow(1 + rate, periods) - 1)

	value, digits = amount, 0
	while value >= 1:
	value = value / 10
	digits += 1
	digits += 3

	remain = amount
	interest_sum, principal_sum, payment_sum = (0, 0, 0)
	print '[等额本息方案] 贷款:%s 利率:%s 期限:%s年'%(data.amount, data.interest_rate, data.years)
	print '\|期数\|月供\|月供利息\|累计利息\|月供本金\|累积本金\|剩余贷款\|结清占比\|月供本金占比\|累积本金占比\|'
	table_format = '\|'
	for n in range(10):
	table_format += ':-:\|'
	print table_format
	for n in range(periods):
	interest = remain * rate
	principal = payment - interest
	interest_sum += interest
	principal_sum += principal
	payment_sum += payment

	remain = remain * (1 + rate) - payment
	format = '\|%%03d\|%%9.2f\|%%9.2f\|%%%d.2f\|%%9.2f\|%%%d.2f\|%%%d.2f\|'%(digits, digits, digits)
	print format%(n + 1, payment, interest, interest_sum, principal, principal_sum, remain), \
	'%6.2f%%\|'%((1 - remain / amount) * 100), \
	'%6.2f%%\|'%(100 * principal / payment), '%6.2f%%\|'%(100 * principal_sum / payment_sum)


	def pay_with_equal_principal(data):
	amount = float(data.amount)
	rate = float(data.interest_rate) / 100 / 12
	periods = int(data.years) * 12
	print amount, rate, periods

	fixed_payment = amount / periods

	value, digits = amount, 0
	while value >= 1:
	value = value / 10
	digits += 1
	digits += 3

	remain = amount
	interest_sum, principal_sum, payment_sum = (0, 0, 0)
	print '[等额本金方案] 贷款:%s 利率:%s 期限:%s年'%(data.amount, data.interest_rate, data.years)
	print '\|期数\|月供\|月供利息\|累计利息\|月供本金\|累积本金\|剩余贷款\|结清占比\|月供本金占比\|累积本金占比\|'
	table_format = '\|'
	for n in range(10):
	table_format += ':-:\|'
	print table_format
	for n in range(periods):
	interest = remain * rate
	payment = fixed_payment + interest
	principal = fixed_payment
	interest_sum += interest
	principal_sum += principal
	payment_sum += payment

	remain -= fixed_payment
	format = '\|%%03d\|%%9.2f\|%%9.2f\|%%%d.2f\|%%9.2f\|%%%d.2f\|%%%d.2f\|'%(digits, digits, digits)
	print format%(n + 1, payment, interest, interest_sum, principal, principal_sum, remain), \
	'%6.2f%%\|'%((1 - remain / amount) * 100), \
	'%6.2f%%\|'%(100 * principal / payment), '%6.2f%%\|'%(100 * principal_sum / payment_sum)

	def caculate_mortage_rate():
	rate, periods = 4.0, 30 * 12
	print periods
	print '\|利率\|月供比例\|300万\|350万\|400万\|450万\|500万\|550万\|600万\|650万\|'
	table_format = '\|'
	for n in range(10):
	table_format += ':-:\|'
	print table_format
	while rate <= 6.4:
	rate_adj = rate / 100 / 12
	precent = rate_adj * pow(1 + rate_adj, periods) / (pow(1 + rate_adj, periods) - 1)
	print '\|%3.1f\|%6.4f%%\|%8.2f\|%8.2f\|%8.2f\|%8.2f\|%8.2f\|%8.2f\|%8.2f\|%8.2f\|'%(rate, precent * 100, \
	3000000precent, 3500000precent,\
	4000000precent, 4500000precent,\
	5000000precent, 5500000precent,\
	6000000precent, 6500000precent)
	rate += 0.1

	def main():
	parser = argparse.ArgumentParser()
	parser.add_argument('-y', '--years', default = 30, required = True, help = 'number of loan years')
	parser.add_argument('-r', '--interest-rate', required = True, help = 'bank loan interest rate')
	parser.add_argument('-n', '--amount', required = True, help = 'total loan amount')
	data = parser.parse_args(sys.argv[1:])

	pay_with_equal_amount(data)
	pay_with_equal_principal(data)
	caculate_mortage_rate()

	if __name__ == '__main__':
	main()