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python - 如何将多个字典放在一个列表中

问题描述

我创建了一个字典：

new_list = {}

这使，

    {'date': '13/09/2020', 'day': '13', 'month': '9', 'year': '2020', 'cases': '35', 'deaths': '0', 
    'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 
    'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.3090878'}
    {'date': '12/9/20', 'day': '12', 'month': '9', 'year': '2020', 'cases': '34', 'deaths': '0', 
    'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 
    'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.22496971'}
    {'date': '11/9/20', 'day': '11', 'month': '9', 'year': '2020', 'cases': '28', 'deaths': '0', 
    'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 
    'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.16450983'}

但现在我想把这本词典添加到列表中

dataset= [new_list]

这使，

[{'date': '13/09/2020', 'day': '13', 'month': '9', 'year': '2020', 'cases': '35', 'deaths': '0', 'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.3090878'}]
[{'date': '12/9/20', 'day': '12', 'month': '9', 'year': '2020', 'cases': '34', 'deaths': '0', 'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.22496971'}]
[{'date': '11/9/20', 'day': '11', 'month': '9', 'year': '2020', 'cases': '28', 'deaths': '0', 'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.16450983'}]

但是我试图得到结果（所以只有“[]”在开始和结束时），因为那样我可以做数据集[0:2]（否则它会给我'Nonetype'对象不可下标）和它只会给出前两个字典

[{'date': '13/09/2020', 'day': '13', 'month': '9', 'year': '2020', 'cases': '35', 'deaths': '0', 'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.3090878'},
{'date': '12/9/20', 'day': '12', 'month': '9', 'year': '2020', 'cases': '34', 'deaths': '0', 'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.22496971'},
{'date': '11/9/20', 'day': '11', 'month': '9', 'year': '2020', 'cases': '28', 'deaths': '0', 'countriesAndTerritories': 'Afghanistan', 'countryTerritoryId': 'AF', 'countryTerritoryCode': 'AFG', 'population2019': '38041757', 'continent': 'Asia', 'cumulativeper1000002Weeks': '1.16450983'}]

我的代码如下：

import csv
def read_dataset() -> List[Dict[str,str]]:
    dataset = []
    with open('covid-19.csv', 'r') as file:
        reader = csv.reader(file)
        no_head = next(reader, None)
       
        for row in reader:
            lst = [
                'date',
                'day', 
                'month', 
                'year',
                'cases', 
                'deaths', 
                'countriesAndTerritories', 
                'countryTerritoryId', 
                'countryTerritoryCode', 
                'population2019', 
                'continent',
                'cumulativeper1000002Weeks',
            ]
            new_list = {}
            for x in range(len(lst)):
                new_list[lst[x]] = row[x]
            dataset= [new_list]
            #print(dataset)
            
dataset = read_dataset()
print(dataset[0:2])

标签： pythonlistdictionary

解决方案

import csv
def read_dataset() -> List[Dict[str,str]]:
    dataset = []
    with open('covid-19.csv', 'r') as file:
        reader = csv.reader(file)
        no_head = next(reader, None)
    
        for row in reader:
            lst = [
                'date',
                'day', 
                'month', 
                'year',
                'cases', 
                'deaths', 
                'countriesAndTerritories', 
                'countryTerritoryId', 
                'countryTerritoryCode', 
                'population2019', 
                'continent',
                'cumulativeper1000002Weeks',
            ]
            new_list = {}
            for x in range(len(lst)):
                new_list[lst[x]] = row[x]
            dataset.append(new_list)
            #print(dataset)
    return dataset
            
dataset = read_dataset()
print(dataset[0:2])

不同之处在于您必须使用：

dataset.append(new_list)

functon，它在末尾追加 new_list （这是一个字典，有点混乱，注意变量名！）

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