1 #coding=utf-8
 2 '''
 3 北大4.0
 4 成绩    学分
 5 100～90    4.0
 6 89～85    3.7
 7 84～82    3.3
 8 81～78    3.0
 9 77～75    2.7
10 74～72    2.3
11 71～68    2.0
12 67～64    1.5
13 63～60    1.0
14 59～0    0
15 平均学分绩点=∑(课程学分×成绩绩点)/∑课程学分=各门课程学分绩点之和/各门课程学分数之和
16 '''
17 filename='./myscore.txt'
18 list1=[]
19 def cal():
20     fr=open(filename)
21     for line in fr.readlines():
22         line1=line.strip("\n").split(",")
23         # print(line1)
24         a=float(line1[0])
25         b=float(line1[1])
26         if(a>=90):
27             list1.append((a,(b,4.0)))
28         if(a>=85 and a<=89):
29             list1.append((a,(b,3.7)))
30         if(a>=82 and a<=84):
31             list1.append((a,(b,3.3)))
32         if(a>=78 and a<=81):
33             list1.append((a,(b,3.0)))
34         if(a>=75 and a<=77):
35             list1.append((a,(b,2.7)))
36         if(a>=72 and a<=74):
37             list1.append((a,(b,2.3)))
38         if(a>=68 and a<=71):
39             list1.append((a,(b,2.0)))
40         if(a>=64 and a<=67):
41             list1.append((a,(b,1.5)))
42         if(a>=60 and a<=63):
43             list1.append((a,(b,1.0)))
44         if(a<60):
45             list1.append((a,(b,0.0)))
46 
47     # print(list1)
48     # print(list1.keys())
49     # print(list1.values())
50     c=list1
51     sum_p=0
52     sum_s=0
53     # print(c)
54     for i in range(len(c)):
55         sum_p=sum_p+c[i][1][0]*c[i][1][1]
56         sum_s=sum_s+c[i][1][0]
57     # print(sum_p)
58     # print(sum_s)
59     result=sum_p/sum_s
60     print("北大4.0(GPA):%.2f"%result)
61 
62 if __name__ == '__main__':
63     cal()