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python - 从字典列表中提取键和多个值的 Pythonic 方法

问题描述

我有一些有效的代码，从文本文件中读取数据作为字典列表，代码从 for 循环中的每个字典中获取键和值。虽然它有效，但我确信有比下面的更好的方法来做到这一点：

代码

data_list = [{'Clk': '190', '50%': '5.3149999999999995', '100%': '4.715'}, 
{'Clk': '195', '50%': '5.295', '100%': '4.765'}, 
{'Clk': '200', '50%': '5.395', '100%': '4.9'}, 
{'Clk': '205', '50%': '5.55', '100%': '4.970000000000001'},
 {'Clk': '210', '50%': '5.68', '100%': '5.005'}, 
 {'Clk': '215', '50%': '5.725', '100%': '5.08'}, 
 {'Clk': '220', '50%': '5.85', '100%': '5.215'}, 
 {'Clk': '225', '50%': '6.03', '100%': '5.35'}, 
 {'Clk': '230', '50%': '6.140000000000001', '100%': '5.395'},
  {'Clk': '235', '50%': '6.074999999999999', '100%': '5.37'}, 
  {'Clk': '240', '50%': '6.02', '100%': '5.345'}, 
  {'Clk': '245', '50%': '6.025', '100%': '5.49'}, 
{'Clk': '290', '50%': '5.67', '100%': '5.37'}]

#print(data_list)
#print('\n'*3)
Clk = []
av_50 = []
av_100 = []
for dicty in data_list:
    for k,v in dicty.items():
        #print("  ", v)
        if k == "Clk":
            Clk.append(dicty["Clk"])
        if k == "50%":
            av_50.append(dicty["50%"])
        if k == "100%":
            av_100.append(dicty["100%"])
print('\n'*3)
print(Clk)
print('\n')
print(av_50)
print('\n')
print(av_100)

输出

['190', '195', '200', '205', '210', '215', '220', '225', '230', '235', '240', '245', '290']


['5.3149999999999995', '5.295', '5.395', '5.55', '5.68', '5.725', '5.85', '6.03', '6.140000000000001', '6.074999999999999', '6.02', '6.025', '5.67']


['4.715', '4.765', '4.9', '4.970000000000001', '5.005', '5.08', '5.215', '5.35', '5.395', '5.37', '5.345', '5.49', '5.37']

标签： pythonlistdictionary

解决方案

您可以使用 zip 浏览字典并将 3 个字段映射到各个列表：

data_list = [{'Clk': '190', '50%': '5.3149999999999995', '100%': '4.715'}, 
    {'Clk': '195', '50%': '5.295', '100%': '4.765'}, 
    {'Clk': '200', '50%': '5.395', '100%': '4.9'}, 
    {'Clk': '205', '50%': '5.55', '100%': '4.970000000000001'},
    {'Clk': '210', '50%': '5.68', '100%': '5.005'}, 
    {'Clk': '215', '50%': '5.725', '100%': '5.08'}, 
    {'Clk': '220', '50%': '5.85', '100%': '5.215'}, 
    {'Clk': '225', '50%': '6.03', '100%': '5.35'}, 
    {'Clk': '230', '50%': '6.140000000000001', '100%': '5.395'},
    {'Clk': '235', '50%': '6.074999999999999', '100%': '5.37'}, 
    {'Clk': '240', '50%': '6.02', '100%': '5.345'}, 
    {'Clk': '245', '50%': '6.025', '100%': '5.49'}, 
    {'Clk': '290', '50%': '5.67', '100%': '5.37'}
]

Clk, av_50, av_100 = map(list,zip(*((d["Clk"],d["50%"],d["100%"]) for d in data_list)))

print(Clk)
print(av_50)
print(av_100)

['190', '195', '200', '205', '210', '215', '220', '225', '230', '235', '240', '245', '290']
['5.3149999999999995', '5.295', '5.395', '5.55', '5.68', '5.725', '5.85', '6.03', '6.140000000000001', '6.074999999999999', '6.02', '6.025', '5.67']
['4.715', '4.765', '4.9', '4.970000000000001', '5.005', '5.08', '5.215', '5.35', '5.395', '5.37', '5.345', '5.49', '5.37']

对于更通用的公式，您可以将键与列表理解分开：

keys = ("Clk","50%","100%")
Clk,av_50,av_100 = map(list,zip(*(map(d.get,keys) for d in data_list)))

这将允许创建通用密钥提取函数：

def listKeys(D,*keys):
    return map(list,zip(*(map(d.get,keys) for d in D)))

Clk,av_50,av_100 = listKeys(data_list,"Clk","50%","100%")

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