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使用Python中的字典循环浏览字典列表的正确方法

python

使用Python中的字典循环浏览字典列表的正确方法,python,Python,我有一份车辆清单和一份过滤器清单。代码如下： filters = { 'make': 'SKODA', 'model': 'Fabia', 'fuel': 'Diesel', 'transmission': '', 'registration_year': '', 'price': {'start': 10000, 'stop': 12000} } vehicles = [ {'make': 'AUDI', 'model': 'Q2 Dsl', 'type': '1

我有一份车辆清单和一份过滤器清单。代码如下：

filters = {
  'make': 'SKODA',
  'model': 'Fabia',
  'fuel': 'Diesel',
  'transmission': '',
  'registration_year': '',
  'price': {'start': 10000, 'stop': 12000}
}

vehicles = [
  {'make': 'AUDI', 'model': 'Q2 Dsl', 'type': '1.6 TDi Sport', 'fuel': 'Diesel', 'mileage': '19896', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 17800}, 
  {'make': 'AUDI', 'model': 'A6 SW Dsl', 'type': '2.0 TDi S line', 'fuel': 'Diesel', 'mileage': '87354', 'registration_year': '2013', 'transmission': 'Handbediende versnellingsbak', 'price': 52000},
  {'make': 'SKODA', 'model': 'Fabia', 'type': '1.6 CR TDi GreenLine Active DPF', 'fuel': 'Diesel', 'mileage': '90613', 'registration_year': '2012', 'transmission': 'Handbediende versnellingsbak', 'price': 11000},
  {'make': 'AUDI', 'model': 'A4 SW Dsl', 'type': '2.0 TDi S tronic', 'fuel': 'Diesel', 'mileage': '47402', 'registration_year': '2016', 'transmission': 'Sequentiele bak', 'price': 93000},
  {'make': 'VOLKSWAGEN', 'model': 'Touran', 'type': '1.4 TSI Trendline', 'fuel': 'Essence', 'mileage': '28588', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 87000},
  {'make': 'AUDI', 'model': 'A4 Dsl', 'type': '2.0 TDi', 'fuel': 'Diesel', 'mileage': '66053', 'registration_year': '2014', 'transmission': 'Handbediende versnellingsbak', 'price': 62000}
]

def filter_item(vehicle):
  vehicles = []
  for key, value in filters.items():
    if key == "price":
      if vehicle[key] > value['start'] and vehicle[key] < value['stop']:
        vehicles.append(vehicle)
    else:
      if vehicle[key] == value:
        vehicles.append(vehicle)
  return vehicles

result = py_.filter(vehicles, lambda x: filter_item(x))
过滤器字典如下所示：

filters = {
  'make': 'SKODA',
  'model': 'Fabia',
  'fuel': 'Diesel',
  'transmission': '',
  'registration_year': '',
  'price': {'start': 10000, 'stop': 12000}
}

vehicles = [
  {'make': 'AUDI', 'model': 'Q2 Dsl', 'type': '1.6 TDi Sport', 'fuel': 'Diesel', 'mileage': '19896', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 17800}, 
  {'make': 'AUDI', 'model': 'A6 SW Dsl', 'type': '2.0 TDi S line', 'fuel': 'Diesel', 'mileage': '87354', 'registration_year': '2013', 'transmission': 'Handbediende versnellingsbak', 'price': 52000},
  {'make': 'SKODA', 'model': 'Fabia', 'type': '1.6 CR TDi GreenLine Active DPF', 'fuel': 'Diesel', 'mileage': '90613', 'registration_year': '2012', 'transmission': 'Handbediende versnellingsbak', 'price': 11000},
  {'make': 'AUDI', 'model': 'A4 SW Dsl', 'type': '2.0 TDi S tronic', 'fuel': 'Diesel', 'mileage': '47402', 'registration_year': '2016', 'transmission': 'Sequentiele bak', 'price': 93000},
  {'make': 'VOLKSWAGEN', 'model': 'Touran', 'type': '1.4 TSI Trendline', 'fuel': 'Essence', 'mileage': '28588', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 87000},
  {'make': 'AUDI', 'model': 'A4 Dsl', 'type': '2.0 TDi', 'fuel': 'Diesel', 'mileage': '66053', 'registration_year': '2014', 'transmission': 'Handbediende versnellingsbak', 'price': 62000}
]

def filter_item(vehicle):
  vehicles = []
  for key, value in filters.items():
    if key == "price":
      if vehicle[key] > value['start'] and vehicle[key] < value['stop']:
        vehicles.append(vehicle)
    else:
      if vehicle[key] == value:
        vehicles.append(vehicle)
  return vehicles

result = py_.filter(vehicles, lambda x: filter_item(x))
车辆清单如下：

filters = {
  'make': 'SKODA',
  'model': 'Fabia',
  'fuel': 'Diesel',
  'transmission': '',
  'registration_year': '',
  'price': {'start': 10000, 'stop': 12000}
}

vehicles = [
  {'make': 'AUDI', 'model': 'Q2 Dsl', 'type': '1.6 TDi Sport', 'fuel': 'Diesel', 'mileage': '19896', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 17800}, 
  {'make': 'AUDI', 'model': 'A6 SW Dsl', 'type': '2.0 TDi S line', 'fuel': 'Diesel', 'mileage': '87354', 'registration_year': '2013', 'transmission': 'Handbediende versnellingsbak', 'price': 52000},
  {'make': 'SKODA', 'model': 'Fabia', 'type': '1.6 CR TDi GreenLine Active DPF', 'fuel': 'Diesel', 'mileage': '90613', 'registration_year': '2012', 'transmission': 'Handbediende versnellingsbak', 'price': 11000},
  {'make': 'AUDI', 'model': 'A4 SW Dsl', 'type': '2.0 TDi S tronic', 'fuel': 'Diesel', 'mileage': '47402', 'registration_year': '2016', 'transmission': 'Sequentiele bak', 'price': 93000},
  {'make': 'VOLKSWAGEN', 'model': 'Touran', 'type': '1.4 TSI Trendline', 'fuel': 'Essence', 'mileage': '28588', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 87000},
  {'make': 'AUDI', 'model': 'A4 Dsl', 'type': '2.0 TDi', 'fuel': 'Diesel', 'mileage': '66053', 'registration_year': '2014', 'transmission': 'Handbediende versnellingsbak', 'price': 62000}
]

def filter_item(vehicle):
  vehicles = []
  for key, value in filters.items():
    if key == "price":
      if vehicle[key] > value['start'] and vehicle[key] < value['stop']:
        vehicles.append(vehicle)
    else:
      if vehicle[key] == value:
        vehicles.append(vehicle)
  return vehicles

result = py_.filter(vehicles, lambda x: filter_item(x))
因此，我希望通过所有车辆和所有过滤器进行循环，并仅返回与过滤器匹配的车辆。在这种情况下，我应该只购买斯柯达

我尝试了
pydash
library，但没有成功

我试过的方法如下：

filters = {
  'make': 'SKODA',
  'model': 'Fabia',
  'fuel': 'Diesel',
  'transmission': '',
  'registration_year': '',
  'price': {'start': 10000, 'stop': 12000}
}

vehicles = [
  {'make': 'AUDI', 'model': 'Q2 Dsl', 'type': '1.6 TDi Sport', 'fuel': 'Diesel', 'mileage': '19896', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 17800}, 
  {'make': 'AUDI', 'model': 'A6 SW Dsl', 'type': '2.0 TDi S line', 'fuel': 'Diesel', 'mileage': '87354', 'registration_year': '2013', 'transmission': 'Handbediende versnellingsbak', 'price': 52000},
  {'make': 'SKODA', 'model': 'Fabia', 'type': '1.6 CR TDi GreenLine Active DPF', 'fuel': 'Diesel', 'mileage': '90613', 'registration_year': '2012', 'transmission': 'Handbediende versnellingsbak', 'price': 11000},
  {'make': 'AUDI', 'model': 'A4 SW Dsl', 'type': '2.0 TDi S tronic', 'fuel': 'Diesel', 'mileage': '47402', 'registration_year': '2016', 'transmission': 'Sequentiele bak', 'price': 93000},
  {'make': 'VOLKSWAGEN', 'model': 'Touran', 'type': '1.4 TSI Trendline', 'fuel': 'Essence', 'mileage': '28588', 'registration_year': '2017', 'transmission': 'Handbediende versnellingsbak', 'price': 87000},
  {'make': 'AUDI', 'model': 'A4 Dsl', 'type': '2.0 TDi', 'fuel': 'Diesel', 'mileage': '66053', 'registration_year': '2014', 'transmission': 'Handbediende versnellingsbak', 'price': 62000}
]

def filter_item(vehicle):
  vehicles = []
  for key, value in filters.items():
    if key == "price":
      if vehicle[key] > value['start'] and vehicle[key] < value['stop']:
        vehicles.append(vehicle)
    else:
      if vehicle[key] == value:
        vehicles.append(vehicle)
  return vehicles

result = py_.filter(vehicles, lambda x: filter_item(x))

def过滤器项目（车辆）：
车辆=[]
对于键，filters.items（）中的值：
如果键==“价格”：
如果车辆[钥匙]>值['start']和车辆[钥匙]<值['stop']：
车辆。附加（车辆）
其他：
如果车辆[钥匙]==值：
车辆。附加（车辆）
返回车辆
结果=过滤器（车辆，λx：过滤器项目（x））
但在这种情况下，我得到的是所有燃油类型为柴油的车辆，但如果从0开始，我应该只得到第二种，因此只有斯柯达。

知道我该怎么做吗？还有更好的方法或更干净的代码吗

您需要检查所有过滤器条件，下面是一个python内置过滤器的示例：

def filter_item(vehicle):
    vehicles = []
    for key, value in filters.items():
        if not value: # skip empty filter
            continue
        if key == "price":
            if vehicle[key] > value['start'] and vehicle[key] < value['stop']:
                continue
        else:
            if vehicle[key] == value:
                continue
        return False # no filter matched
    return True


result = filter(filter_item, vehicles)
注意：传递给fitler的回调函数返回true，表示当前值应该包含在结果中。

我认为价格范围应该从
过滤器中分离出来。这很尴尬，因为它是唯一一个不能直接与车辆同一钥匙对应值匹配的钥匙

我会这样写


>>> filters = {
...:  'make': 'SKODA',
...:  'model': 'Fabia',
...:  'fuel': 'Diesel',
...:  'transmission': '',
...:  'registration_year': '',
...:}
>>> price_range = range(10000, 12000 + 1)
>>>
>>> [vehicle['make'] for vehicle in vehicles if
...:all(vehicle.get(k) == v for k, v in filters.items() if v) and
...:vehicle['price'] in price_range]
>>> ['SKODA']



>>> [vehicle for vehicle in vehicles if
...:all(vehicle.get(k) == v for k, v in filters.items() if v) and
...:vehicle['price'] in price_range]
>>> 
[{'fuel': 'Diesel',
  'make': 'SKODA',
  'mileage': '90613',
  'model': 'Fabia',
  'price': 11000,
  'registration_year': '2012',
  'transmission': 'Handbediende versnellingsbak',
  'type': '1.6 CR TDi GreenLine Active DPF'}]


还是像这样


>>> filters = {
...:  'make': 'SKODA',
...:  'model': 'Fabia',
...:  'fuel': 'Diesel',
...:  'transmission': '',
...:  'registration_year': '',
...:}
>>> price_range = range(10000, 12000 + 1)
>>>
>>> [vehicle['make'] for vehicle in vehicles if
...:all(vehicle.get(k) == v for k, v in filters.items() if v) and
...:vehicle['price'] in price_range]
>>> ['SKODA']



>>> [vehicle for vehicle in vehicles if
...:all(vehicle.get(k) == v for k, v in filters.items() if v) and
...:vehicle['price'] in price_range]
>>> 
[{'fuel': 'Diesel',
  'make': 'SKODA',
  'mileage': '90613',
  'model': 'Fabia',
  'price': 11000,
  'registration_year': '2012',
  'transmission': 'Handbediende versnellingsbak',
  'type': '1.6 CR TDi GreenLine Active DPF'}]


以防您需要匹配的整车词典