从所有字典中获取特定键的值

Question

I have a list of dictionary like this,

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'}]

I need to iterate over the list of dictionaries and get the DriverValue of all dictionary without repeating the SegmentName and DriverName and PortfolioId.

This is my code so far,

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)

The DriverValue is always empty in the list. Where I am doing wrong?

Sample Output:

{
    "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

Theres probably a more elegant approach to this, but this will get you the key value pairs for each occurrence of the "drivervalue" key in the list of dictionaries, and then store the values in your list mm:

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

Just played around and another approach is:

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

Where p will be a list of the values. Hope this helps.