如何在 Python 中从该字典中提取值？答案

【问题标题】：how can I extract values from this dictionary in Python?如何在 Python 中从该字典中提取值？
【发布时间】：2022-03-06 00:59:36
【问题描述】：

我有一本这样的字典：

{"message":"{\"_\":\"user\",\"pFlags\":{\"contact\":true},\"flags\":2175,\"id\":379951860,\"access_hash\":\"6967195540985199805\",\"first_name\":\"پژوا\",\"last_name\":\"روزبهی\",\"username\":\"mramtd2\",\"phone\":\"989157145632\",\"photo\":{\"_\":\"userProfilePhoto\",\"photo_id\":\"1631880813210609625\",\"photo_small\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476387,\"secret\":\"655623158723369503\"},\"photo_big\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476389,\"secret\":\"13993366131879811943\"}},\"status\":{\"_\":\"userStatusOffline\",\"was_online\":1558046876}}","phone":"989157145632","@version":"1","typ":"telegram_contacts","access_hash":"6967195540985199805","id":379951860,"@timestamp":"2020-01-26T13:50:12.793Z","path":"/home/user/mirror_01/users_5d65f610ec18aa615a5f580c.log","username":"mramtd2","type":"redis","flags":2175,"host":"ubuntu","imported_from":"telegram_contacts"}

如何从该字典中提取 first_name、last_name、id 和 phone 值？

【问题讨论】：

这个字典是否来自 JSON 文件/字符串？
@FélixHerbinet 来自文本文件的编号
你能复制/粘贴文件的内容吗？

标签： python dictionary dataset key-value

【解决方案1】：

另外，假设你的文件有新行分隔的字典，使用下面的代码解决了这个问题：

import json
fo = open(r"C:\Users\Downloads\test.txt", "r")
for each_line in fo.readlines():
    print(json.loads(json.loads(each_line)['message'])['first_name'])
    print(json.loads(json.loads(each_line)['message'])['last_name'])
    print(json.loads(json.loads(each_line)['message'])['id'])
    print(json.loads(json.loads(each_line)['message'])['phone'])

【讨论】：

【解决方案2】：

import json

# I have assumed your dictionary like that
data = {"message":"{\"_\":\"user\",\"pFlags\":{\"contact\":true},\"flags\":2175,\"id\":379951860,\"access_hash\":\"6967195540985199805\",\"first_name\":\"پژوا\",\"last_name\":\"روزبهی\",\"username\":\"mramtd2\",\"phone\":\"989157145632\",\"photo\":{\"_\":\"userProfilePhoto\",\"photo_id\":\"1631880813210609625\",\"photo_small\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476387,\"secret\":\"655623158723369503\"},\"photo_big\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476389,\"secret\":\"13993366131879811943\"}},\"status\":{\"_\":\"userStatusOffline\",\"was_online\":1558046876}}","phone":"989157145632","@version":"1","typ":"telegram_contacts","access_hash":"6967195540985199805","id":379951860,"@timestamp":"2020-01-26T13:50:12.793Z","path":"/home/user/mirror_01/users_5d65f610ec18aa615a5f580c.log","username":"mramtd2","type":"redis","flags":2175,"host":"ubuntu","imported_from":"telegram_contacts"}

# The data in "message" need to be loaded on JSON format to access it.
data["message"] = json.loads(data["message"])

# Now, you can print or whatever you want with all the data
print(data["message"]["id"])
print(data["message"]["first_name"])
print(data["message"]["last_name"])
print(data["message"]["phone"])  # There is phone info both in data["message"]["phone"] and data["phone"]. They are identical. You can use whichever you want.

# Optional
# If you want, you can assign data["message"] to a variable.
finalData = data["message"]

# Then you can access the info that you need from finalData
print(finalData["first_name"])

【讨论】：

你的回答是对的。但我有一个大文本文件，它有多个这样的字典。我该怎么做？
每一行是否包含一个字典，或者是否有一个包含所有字典的主字典或列表？

【解决方案3】：

您应该使用例如将字符串转换为字典json.loads。然后从普通的嵌套字典中提取like。

例子：

import json
message = mydict["message"]
message_dict = json.loads(message)
message_dict['id']

mydict 是您给定的输入字典。

如果您的 sn-p 显示文件的内容，您可以执行以下操作：

with open(filepath) as file:
    mydict = json.load(file)
message_dict = mydict["message"]
message_dict['id']

【讨论】：

这是一个文本文件
您应该在问题中澄清您的 sn-p 不是代码，而是文件的内容。
如果您能向我们展示一些代码行以更好地了解您卡在哪里，这将非常有帮助。是打开文件吗？是否将值读入变量？是解析json字段吗？

【解决方案4】：

这是另一种方法：

import json

D = {"message":"{\"_\":\"user\",\"pFlags\":{\"contact\":true},\"flags\":2175,\"id\":379951860,\"access_hash\":\"6967195540985199805\",\"first_name\":\"پژوا\",\"last_name\":\"روزبهی\",\"username\":\"mramtd2\",\"phone\":\"989157145632\",\"photo\":{\"_\":\"userProfilePhoto\",\"photo_id\":\"1631880813210609625\",\"photo_small\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476387,\"secret\":\"655623158723369503\"},\"photo_big\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476389,\"secret\":\"13993366131879811943\"}},\"status\":{\"_\":\"userStatusOffline\",\"was_online\":1558046876}}","phone":"989157145632","@version":"1","typ":"telegram_contacts","access_hash":"6967195540985199805","id":379951860,"@timestamp":"2020-01-26T13:50:12.793Z","path":"/home/user/mirror_01/users_5d65f610ec18aa615a5f580c.log","username":"mramtd2","type":"redis","flags":2175,"host":"ubuntu","imported_from":"telegram_contacts"}

data = json.loads(D['message'])

for key in ['first_name', 'last_name', 'phone', 'id']:
    print(f'{key} -> {data.get(key, "?")}')

【讨论】：

【解决方案5】：

您可以使用以下代码提取这些值：

import json

str1 = r'{"message":"{\"_\":\"user\",\"pFlags\":{\"contact\":true},\"flags\":2175,\"id\":379951860,\"access_hash\":\"6967195540985199805\",\"first_name\":\"پژوا\",\"last_name\":\"روزبهی\",\"username\":\"mramtd2\",\"phone\":\"989157145632\",\"photo\":{\"_\":\"userProfilePhoto\",\"photo_id\":\"1631880813210609625\",\"photo_small\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476387,\"secret\":\"655623158723369503\"},\"photo_big\":{\"_\":\"fileLocation\",\"dc_id\":4,\"volume_id\":\"448413446\",\"local_id\":476389,\"secret\":\"13993366131879811943\"}},\"status\":{\"_\":\"userStatusOffline\",\"was_online\":1558046876}}","phone":"989157145632","@version":"1","typ":"telegram_contacts","access_hash":"6967195540985199805","id":379951860,"@timestamp":"2020-01-26T13:50:12.793Z","path":"/home/user/mirror_01/users_5d65f610ec18aa615a5f580c.log","username":"mramtd2","type":"redis","flags":2175,"host":"ubuntu","imported_from":"telegram_contacts"}'

print(json.loads(json.loads(str1)['message'])['first_name'])
print(json.loads(json.loads(str1)['message'])['last_name'])
print(json.loads(json.loads(str1)['message'])['id'])
print(json.loads(json.loads(str1)['message'])['phone'])

【讨论】：