From Python chapter 2 code solution

Here is my answer for book:

从Python开始学编程

Chapter 2, Appendix A, Exam.

https://book.douban.com/subject/26919485/

..

from itertools import repeat

def gen():

int_rate = [0.01, 0.02, 0.03, 0.035, 0.05]

for r in int_rate:

yield r

for r in repeat(0.05):

yield r

def num_year_pay() :

house_price = 500000

year_pay = 30000

year_n = 1

rem = house_price

print(year_pay)

for r in gen():

if rem <=0:

break

print(r)

rem = rem * (1 + r) - year_pay

year_n = year_n + 1

print(rem)

return year_n

if __name__ == "__main__":

print("Number of years to pay loan: ", num_year_pay())

Number of years to pay loan: 31