从所有字典中获取特定键的值

Question

我有一本这样的词典

a = [{'SegmentName': 'FICO High', 'CohortMonthYear': '01-01-2015', 'DriverValue': '0.921996823602789',
      'MonthsOnBooks': '1',
      'CohortQuarterYear': 'Q1 2015', 'PortfolioId': '55dc0e48c95a8a1a2ffb836e', 'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '01-01-2015', 'DriverValue': '0.9123400335106416',
      'MonthsOnBooks': '2', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '01-01-2015', 'DriverValue': '0.9024207736261439',
      'MonthsOnBooks': '3', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '01-01-2015', 'DriverValue': '0.889915542915732',
      'MonthsOnBooks': '4',
      'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'), 'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '01-01-2015', 'DriverValue': '0.8806580068608421',
      'MonthsOnBooks': '5', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '02-01-2015', 'DriverValue': '0.9458702933667549',
      'MonthsOnBooks': '1', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '02-01-2015', 'DriverValue': '0.9335318149106486',
      'MonthsOnBooks': '2', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '02-01-2015', 'DriverValue': '0.9225337221412799',
      'MonthsOnBooks': '3', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '02-01-2015', 'DriverValue': '0.9109689291572624',
      'MonthsOnBooks': '4', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '03-01-2015', 'DriverValue': '0.9092991755453589',
      'MonthsOnBooks': '1', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '03-01-2015', 'DriverValue': '0.8988101317456371',
      'MonthsOnBooks': '2', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '03-01-2015', 'DriverValue': '0.8860809446836048',
      'MonthsOnBooks': '3', 'CohortQuarterYear': 'Q1 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '04-01-2015', 'DriverValue': '0.9471495415096017',
      'MonthsOnBooks': '1', 'CohortQuarterYear': 'Q2 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '04-01-2015', 'DriverValue': '0.9364314248533585',
      'MonthsOnBooks': '2', 'CohortQuarterYear': 'Q2 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'},
     {'SegmentName': 'FICO High', 'CohortMonthYear': '05-01-2015', 'DriverValue': '0.9344317261744861',
      'MonthsOnBooks': '1', 'CohortQuarterYear': 'Q2 2015', 'PortfolioId': ('55dc0e48c95a8a1a2ffb836e'),
      'DriverName': 'Active rate'}]

我需要遍历字典列表并获取所有字典的DriverValue，而不重复SegmentName、DriverName和PortfolioId。你知道吗

到目前为止这是我的密码

mm = []
for i in a:
    ss = {'DriverName': i['DriverName'], 'SegmentName': i['SegmentName'], 'PortfolioId': i['PortfolioId'],
          'DriverValue': []}

    if all([i['DriverName'] == 'DriverName' and i['SegmentName'] == 'SegmentName']):
        ss['DriverValue'].append(i['DriverValue'])

    mm.append(ss)

print(mm)

DriverValue在列表中始终为空。我哪里做错了？你知道吗

样本输出：

{
    "PortfolioId" : ("55d4247b119a612af00eff4b"),
    "DriverName" : "Active rate",
    "SampleData" : [ 
        30, 
        24, 
        6, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9, 
        9
    ]
}

Answer 1

可能有一种更优雅的方法，但这将为字典列表中每次出现的“drivervalue”键获取键值对，然后将值存储在列表mm中：

mm = []
for b in a:
    for key,value in b.items():
        if key == "DriverValue":
            mm.append(value)

只是随便玩玩，另一种方法是：

p = [d['DriverValue'] for d in a]

其中p是值的列表。希望这有帮助。你知道吗