如何使用 Python 从 JSON 获取单个键的值列表

Question

我有这些列表，我想获取名称的值：

[{
  "tr": [{
      "name": "#For5Rs",
      "promoted_content": null,
      "query": "%23For5Rs",
      "events": null
  }, {
      "name": "Javed Bashir",
      "promoted_content": null,
      "query": "%22Javed+Bashir%22",
      "events": null
  }, {
      "name": "Milan Luthria",
      "promoted_content": null,
      "query": "%22Milan+Luthria%22",
      "events": null
  }, {
      "name": "Vidya Balan",
      "promoted_content": null,
      "query": "%22Vidya+Balan%22",
      "events": null
  }],
  "as_of": "2013-08-16T10:31:35Z",
  "created_at": "2013-08-16T10:20:41Z",
  "locations": [{
      "name": "India",
      "woeid": 23424848
  }]
}]

Answer 1

你问的是，"I have a list of dictionaries. Each dictionary has a key "name". How do I get a list of values of all those keys?"

基础知识

使用方括号中的索引访问列表元素。 a[0] 是列表的第一个元素。
使用括号中的键访问字典值。 a["name"] 是 this_value 来自 {"name":this_value}。

使用循环聚合值，如下所示：

aggregator = []
for item in a_list:
    aggregator.append(value_calculated_from(item))

有问题

your_list 没有配对方括号。

我假设

outer_dictionary = your_list[0]
list_of_dictionaries = outer_dictionary['tr']

回答

您可以获得"name"的值列表：

names = []
for dictionary in list_of_dictionaries:
    if "name" in dictionary:
        names.append(dictionary["name"])

Answer 2

我看到您的数据没有完全格式化（编辑前）- 所以我会使用正则表达式-下面的代码从提供的 json STRING(只需附上 """""")

import re
data="""[{
  "tr": [{
      "name": "#For5Rs",
      "promoted_content": null,
      "query": "%23For5Rs",
      "events": null
  }, {
      "name": "Javed Bashir",
      "promoted_content": null,
      "query": "%22Javed+Bashir%22",
      "events": null
  }, {
      "name": "Milan Luthria",
      "promoted_content": null,
      "query": "%22Milan+Luthria%22",
      "events": null
  }, {
      "name": "Vidya Balan",
      "promoted_content": null,
      "query": "%22Vidya+Balan%22",
      "events": null
  }],
  "as_of": "2013-08-16T10:31:35Z",
  "created_at": "2013-08-16T10:20:41Z",
  "locations": [{
      "name": "India",
      "woeid": 23424848
  }]
"""

names=re.findall(r'(?<="name":\s").+(?=",[\s\S]+"promoted_content")',data)
print names

它打印一个列表-

['#For5Rs', 'Javed Bashir', 'Milan Luthria', 'Vidya Balan']

Answer 3

for element in data['tr']:
    print element['name']
    print element['promoted_content']
    print element['query']
    print element['events']

Answer 4

试试这个

for element in data[key]:
   #print your values here

如何使用 Python 从 JSON 获取单个键的值列表

How to get list of values of a single key from JSON using Python

python

json

variables

select

fetch

基础知识

有问题

回答