1 def read_data(): 2 with open("test","r",encoding="utf-8") as f : 3 for data in f: 4 yield data 5 6 g = read_data() 7 8 all_population = sum(eval(dt)["population"] for dt in g) 9 print(all_population ) 10 11 g1 = read_data() 12 13 for res in g1: 14 data_pic = eval(res) 15 print("%s所占全部的比例是%.1f"%(data_pic["city"],round(data_pic["population"]/all_population,3) *100))
文件如下：
{"city":"北京","population":56}
{"city":"上海","population":28}
{"city":"南京","population":30}
{"city":"安徽","population":40}
{"city":"台湾","population":100}
原文：https://www.cnblogs.com/xiesongyou/p/9380615.html