Python中给字典排序的七种方法详解

>>> dic={'a': 4, 'b': 3, 'c': 2, 'd': 1}
>>> sorted(dic.items(), key=lambda x: x[1])
[('d', 1), ('c', 2), ('b', 3), ('a', 4)]

>>> dic={'a': 4, 'b': 3, 'c': 2, 'd': 1}
>>> sorted(dic.items(), key=lambda x: x[1],reverse=True)
{'a': 4, 'b': 3, 'c': 2, 'd': 1}

>>> import operator
>>> sorted(dic.items(), key=operator.itemgetter(1))
[('d', 1), ('c', 2), ('b', 3), ('a', 4)]

operator. itemgetter(item)
operator. itemgetter(*items)

>>>  dic={'a': 4, 'b': 3, 'c': 2, 'd': 1}
>>> tup=[(x[1],x[0]) for x in dic.items()]#元素互换位置
>>> sorted(tup) #排序
[(1, 'd'), (2, 'c'), (3, 'b'), (4, 'a')]
>>> [(x[1],x[0]) for x in dic.items()]
>>> [(x[1],x[0]) for x in tup] #换回原来的位置
>>> [('d', 1), ('c', 2), ('b', 3), ('a', 4)]

from collections import Counter
dic={'a': 4, 'b': 3, 'c': 2, 'd': 1}
count = Counter(dic)
print(list(count.items()))

import pandas as pd  
  
dic = {'a': 4, 'b': 3, 'c': 2, 'd': 1}  
df = pd.DataFrame.from_dict(dic, orient='index').reset_index()  
df.columns = ['key', 'value']  
df_sorted = df.sort_values(by='value').reset_index(drop=True)  
  
# 如果你想要得到一个排序后的字典  
sorted_dic = dict(zip(df_sorted['key'], df_sorted['value']))  
  
print(sorted_dic)  
# 输出: {'d': 1, 'c': 2, 'b': 3, 'a': 4}

def sort_dict_by_value(d, reverse=False):  
    return dict(sorted(d.items(), key=lambda x: x[1], reverse=reverse))  
  
dic = {'a': 4, 'b': 3, 'c': 2, 'd': 1}  
sorted_dic = sort_dict_by_value(dic)  
sorted_dic_desc = sort_dict_by_value(dic, reverse=True)  
  
print(sorted_dic_desc)  
# 输出: {'a': 4, 'b': 3, 'c': 2, 'd': 1}

dic = {'a': 4, 'b': 3, 'c': 2, 'd': 1}  
  
# 使用sorted()和字典推导式按值排序  
sorted_dic = {k: v for k, v in sorted(dic.items(), key=lambda x: x[1])}  
  
print(sorted_dic)  
# 输出: {'d': 1, 'c': 2, 'b': 3, 'a': 4}  
  
# 如果需要降序  
sorted_dic_desc = {k: v for k, v in sorted(dic.items(), key=lambda x: x[1], reverse=True)}  
  
print(sorted_dic_desc)  
# 输出: {'a': 4, 'b': 3, 'c': 2, 'd': 1}