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