标签：count 方案 counter com div 接受 创建 int 对象
怎样找出一个序列中出现次数最多的元素呢？
collections.Counter 类就是专门为这类问题而设计的， 它甚至有一个有用的 most_common() 方法直接给了你答案
from collections import Counter words = [ ‘look‘, ‘into‘, ‘my‘, ‘eyes‘, ‘look‘, ‘into‘, ‘my‘, ‘eyes‘, ‘the‘, ‘eyes‘, ‘the‘, ‘eyes‘, ‘the‘, ‘eyes‘, ‘not‘, ‘around‘, ‘the‘, ‘eyes‘, "don‘t", ‘look‘, ‘around‘, ‘the‘, ‘eyes‘, ‘look‘, ‘into‘, ‘my‘, ‘eyes‘, "you‘re", ‘under‘ ] #创建Counter对象 word_counts=Counter(words) #most_common(n)函数可直接统计top-n top_three=word_counts.most_common(3) print(type(top_three)) <class ‘list‘> print(top_three) [(‘eyes‘, 8), (‘the‘, 5), (‘look‘, 4)]
Counter 对象可以接受任意的由可哈希（hashable）元素构成的序列对象
在底层实现上，一个 Counter 对象就是一个字典，将元素映射到它出现的次数上
print(word_counts[‘look‘]) 4 print(word_counts["you‘re"]) 1
word1 = [ ‘look‘, ‘into‘, ‘my‘, ‘eyes‘, ‘look‘, ‘into‘, ‘my‘, ‘eyes‘, ‘the‘, ‘eyes‘, ‘the‘, ‘eyes‘, ‘the‘, ‘eyes‘, ‘not‘, ‘around‘, ‘the‘, ‘eyes‘, "don‘t", ‘look‘, ‘around‘, ‘the‘, ‘eyes‘, ‘look‘, ‘into‘, ‘my‘, ‘eyes‘, "you‘re", ‘under‘ ] word2 = [‘why‘,‘are‘,‘you‘,‘not‘,‘looking‘,‘in‘,‘my‘,‘eyes‘] a=Counter(word1) b=Counter(word2) print(a) Counter({‘eyes‘: 8, ‘the‘: 5, ‘look‘: 4, ‘into‘: 3, ‘my‘: 3, ‘around‘: 2, ‘not‘: 1, ‘under‘: 1, "you‘re": 1, "don‘t": 1}) print(b) Counter({‘eyes‘: 1, ‘not‘: 1, ‘are‘: 1, ‘you‘: 1, ‘in‘: 1, ‘why‘: 1, ‘my‘: 1, ‘looking‘: 1}) print(a+b) Counter({‘eyes‘: 9, ‘the‘: 5, ‘my‘: 4, ‘look‘: 4, ‘into‘: 3, ‘around‘: 2, ‘not‘: 2, ‘under‘: 1, ‘looking‘: 1, ‘you‘: 1, ‘why‘: 1, ‘in‘: 1, ‘are‘: 1, "you‘re": 1, "don‘t": 1}) print(a-b) Counter({‘eyes‘: 7, ‘the‘: 5, ‘look‘: 4, ‘into‘: 3, ‘around‘: 2, ‘my‘: 2, ‘under‘: 1, "you‘re": 1, "don‘t": 1})
[PY3]——找出一个序列中出现次数最多的元素/collections.Counter 类的用法
标签：count 方案 counter com div 接受 创建 int 对象
原文地址：http://www.cnblogs.com/snsdzjlz320/p/7194150.html
