Question

我想使用Python迭代一个JSON文件并打印一组键。

例如：

import json

KEYS_TO_PRINT = ["id", "channel.title"]
my_data = {"items": [{"id": 1, "channel": {"channelid": "channelid1", "title": "nailed_it1"}}, {"id": 2, "channel": {"channelid": "channelid2", "title": "nailed_it2"}}]}
this_row = []

for item in my_data["items"]:
    for key in KEYS_TO_PRINT:
        try:
            if "." in key:
                split_up = key.split(".")
                print item[split_up[0]][split_up[1]]
            else:
                print item[key]
        except KeyError:
            print "Oops"

然而，它非常丑陋。有更简洁的方式吗？

Answer 1

考虑这样的事情，你可以使用＆＃34;指定一个子项。＆＃34;划分你的钥匙。这是一个例子：

KEYS_TO_EXPORT = ["id", "dateTime", "title", "channel.title"]
item = {"id": 1, "channel": {"title": "nailed_it"}}
this_row = []
for export_key in KEYS_TO_EXPORT:
    try:
        value = item
        for key in export_key.split("."):
            value = value[key]
        this_row.append(str(value).encode('utf-8'))
    except KeyError:
        this_row.append("")

编辑以使用列表：

根据对原始问题的编辑，可以轻松扩展此解决方案以使用项目列表，如下所示。此外，我转而使用.get，就像评论中建议的那样。

KEYS_TO_PRINT = ["id", "channel.title"]
my_data = {"items": [
    {"id": 1, "channel": {"channelid": "channelid1", "title": "nailed_it1"}},
    {"id": 2, "channel": {"channelid": "channelid2", "title": "nailed_it2"}},
    {"id": 3}
]}
this_row = []

for item in my_data["items"]:
    for export_key in KEYS_TO_PRINT:
        value = item
        for key in export_key.split("."):
            value = value.get(key)
            if value == None: break
        this_row.append(str(value).encode('utf-8') if value != None else "")
print this_row

如何在Python列表中序列化JSON密钥？

1 个答案: