python 对给定可迭代集合统计出现频率,并排序的方法

def get_counts(sequence):
 counts = {}
 for x in sequence:
  if x in counts:
   counts[x] += 1
  else:
   counts[x] = 1
 return counts

from collections import defaultdict

def get_counts2(sequence):
 counts = defaultdict(int) #所有的值均会被初始化为0
 for x in sequence:
  counts[x] +=1 
 return counts

from collections import Counter

counts = Counter(sequence)
#其中可以用counts.most_common(10)对出现最多的十个倒序排列

def top_count(count_dic, n=10): #默认取最大的n=10个值
 value_key_pairs = [(count,data) for counts,data in cout_dict.items()]
 value_key_pairs.sort()
 #sorted(value_key_pairs) 两者均可
 return value_key_pairs[-n:]