统计一个列表中的元素出现次数

ZCJ7777

问题表述：编写程序实现统计一个列表中的元素出现的次数，结果用字典表示，其中字典的键应按照升序排列。

例如：

1. lst= [5, 7, 8, 1, 1, 5, 9, 2, 3, 8, 3, 5, 1, 1, 10, 1, 9, 10, 9, 4, 6, 3, 8, 5, 1, 8, 5, 1, 9, 3, 6, 3, 1, 8, 10, 1, 1, 3, 8, 6, 3, 3, 5, 9, 3, 1, 5, 1, 1, 9]
   
2. 
   
3. 
   
4. {1: 13, 2: 1, 3: 9, 4: 1, 5: 7, 6: 3, 7: 1, 8: 6, 9: 6, 10: 3}

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第四时空

1. from collections import Counter, defaultdict
   
2. 
   
3. if __name__ == '__main__':
   
4.     lst = [5, 7, 8, 1, 1, 5, 9, 2, 3, 8, 3, 5, 1, 1, 10, 1, 9, 10, 9, 4, 6, 3, 8, 5, 1, 8, 5, 1, 9, 3, 6, 3, 1, 8, 10, 1, 1, 3, 8, 6, 3, 3, 5, 9, 3, 1, 5, 1, 1, 9]
   
5.    
   
6.     print(dict(sorted(Counter(lst).items())))
   
7. 
   
8.     results = {}
   
9.     for i in lst:
   
10.         x = results.setdefault(i, 0)
    
11.         results[i] = x + 1
    
12.     print(dict(sorted(results.items())))
    
13. 
    
14.     results = defaultdict(int)
    
15.     for i in lst:
    
16.         results[i] += 1
    
17.     print(dict(sorted(results.items())))

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moc

1. from functools import reduce
   
2. lst= [5, 7, 8, 1, 1, 5, 9, 2, 3, 8, 3, 5, 1, 1, 10, 1, 9, 10, 9, 4, 6, 3, 8, 5, 1, 8, 5, 1, 9, 3, 6, 3, 1, 8, 10, 1, 1, 3, 8, 6, 3, 3, 5, 9, 3, 1, 5, 1, 1, 9]
   
3. lst.sort()
   
4. def paixu(dic, lst):
   
5.     if lst not in dic:
   
6.         dic[lst] = 1
   
7.     else:
   
8.         dic[lst] += 1
   
9.     return dic
   
10. dic = reduce(paixu, lst, {})
    
11. print(dic)

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qichq_7

前几天面试碰到类似的题目，找一个列表中重复的元素，并按重复的次数降序排列，坐标：深圳，随手科技