如何将python字符串数据转换为列表或dict？

Question

This is my response code from GCM-python,

{"multicast_id":6343554431392278573,"success":5,"failure":15,"canonical_ids":0,"results":[{"message_id":"0:1380910865603840%356b
9054f9fd7ecd"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":
"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"message_id":"0:1380910865592683%356b9054f9fd7ecd"},{"erro
r":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"er
ror":"NotRegistered"},{"message_id":"0:1380910865600910%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"message_id":"0:1380910865
596592%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"message_id":"0:1380910865595499%356b9054f9fd7ecd"}]}

When i get this response, i want to collect all error keys from dictionary...but it seems like it is a string and i'll try dump in json using json.dumps() and then remove slashes but not working for me, not even ast working. I try this one python json dumps . What am i missing there? please help me in this.

Answer 1

If it is a string, load it, don't dump it:

#! /usr/bin/python3

import json

a = '''{"multicast_id":6343554431392278573,"success":5,"failure":15,"canonical_ids":0,"results":[{"message_id":"0:1380910865603840%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":
"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"message_id":"0:1380910865592683%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"message_id":"0:1380910865600910%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"message_id":"0:1380910865596592%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"message_id":"0:1380910865595499%356b9054f9fd7ecd"}]}'''

j = json.loads(a)
errors = [d for d in j ['results'] if 'error' in d]
print(errors)

Answer 2

As the data you receive is a valid Python data, you can simply use [ast.literal_eval][1]

Demo

import ast
data = '''{"multicast_id":6343554431392278573,"success":5,"failure":15,"canonical_ids":0,"results":[{"message_id":"0:1380910865603840%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":
"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"message_id":"0:1380910865592683%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"error":"NotRegistered"},{"message_id":"0:1380910865600910%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"message_id":"0:1380910865596592%356b9054f9fd7ecd"},{"error":"NotRegistered"},{"message_id":"0:1380910865595499%356b9054f9fd7ecd"}]}'''

>>> pp.pprint(ast.literal_eval(data))
{   'canonical_ids': 0,
    'failure': 15,
    'multicast_id': 6343554431392278573L,
    'results': [   {   'message_id': '0:1380910865603840%356b9054f9fd7ecd'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'message_id': '0:1380910865592683%356b9054f9fd7ecd'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'error': 'NotRegistered'},
                   {   'message_id': '0:1380910865600910%356b9054f9fd7ecd'},
                   {   'error': 'NotRegistered'},
                   {   'message_id': '0:1380910865596592%356b9054f9fd7ecd'},
                   {   'error': 'NotRegistered'},
                   {   'message_id': '0:1380910865595499%356b9054f9fd7ecd'}],
    'success': 5}
>>> 

Followed by dumping the errors

>>> pp.pprint([elem['error'] for elem in ast.literal_eval(data)['results'] if 'error' in elem])
[   'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered',
    'NotRegistered']