从字典列表中创建嵌套的 json 对象
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【中文标题】从字典列表中创建嵌套的 json 对象【英文标题】：Create nested json object out of a list of dicts 【发布时间】：2019-04-02 18:32:31 【问题描述】：我想将字典列表翻译成嵌套的.json 文件对象。我有一个字典列表，字典中的一个字段指示特定字段是否应该嵌套在 .json 文件中的哪个位置，如果是，则指示。
我可以将内容嵌套到适当的表中，但是让它们嵌套在字段中的更下方会让我陷入循环。
我的数据采用以下格式：
table_list = [
"Table": "table1", "Field": "field1", "Description": "description1", "Type": "STR",
"Table": "table1", "Field": "field2", "Description": "description2", "Type": "STR",
"Table": "table1", "Field": "field3", "Description": "description3", "Type": "STR",
"Table": "table1", "Field": "field4", "Description": "description4", "Type": "STR",
"Table": "table1", "Field": "field5", "Description": "description5", "Type": "RECORD",
"Table": "table1", "Field": "field5.nest1", "Description": "description6", "Type": "STR",
"Table": "table1", "Field": "field5.nest2", "Description": "description7", "Type": "STR",
"Table": "table1", "Field": "field5.nest3", "Description": "description8", "Type": "STR",
"Table": "table1", "Field": "field5.nest4", "Description": "description9", "Type": "RECORD",
"Table": "table1", "Field": "field5.nest4.nest1", "Description": "description10", "Type": "STR",
"Table": "table1", "Field": "field5.nest4.nest2", "Description": "description11", "Type": "STR",
"Table": "table2", "Field": "field1", "Description": "description1", "Type": "STR"
]
我希望它输出为这种格式（抱歉有任何拼写错误）：
"table1": [
"Field": "field1",
"Description": "description1",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field2",
"Description": "description2",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field3",
"Description": "description3",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field4",
"Description": "description4",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field5",
"Description": "description5",
"Mode": "REPEATED",
"Type": "RECORD",
"Fields": [
"Field": "nest1",
"Description": "description6",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest2",
"Description": "description7",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest3",
"Description": "description8",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest4",
"Description": "description9",
"Mode": "REPEATED",
"Type": "RECORD",
"Fields": [
"Field": "nest1",
"Description": "description10",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest2",
"Description": "description11",
"Mode": "NULLABLE",
"Type": "STR"
]
]
]
"table2": [
"Field": "field1",
"Description": "description1",
"Mode": "NULLABLE",
"Type": "STR"
,
]
我无法让nest1 和nest2 在现有dict 中创建一个新字段，其中包含一个可以添加到carying 深度的开放列表。本例中的巢穴只有 3 层深，但我可能需要最多达到 15 层。
我的代码将在第一级使用"Table" 应用此代码，但进入字段以添加到该列表具有挑战性，我还没有找到具有完全相同问题的问题。
我看到很多人试图通过展平嵌套结构来反向执行此操作，但我正在尝试创建嵌套。
import json
def create_schema(file_to_read):
all_tables =
for row in file_to_read:
if row['Table'] in all_tables.keys():
all_tables[row['Table']].append("Mode": "NULLABLE",
"Field": row['Field'],
"Type": row['Type'],
"Description": row['Description'])
else:
all_tables[row['Table']] = []
all_tables[row['Table']].append("Mode": "NULLABLE",
"Field": row['Field'],
"Type": row['Type'],
"Description": row['Description'])
return json.dumps(all_tables, indent=4, sort_keys=True)
我实际使用此功能得到的是：
"table1": [
"Field": "field1",
"Description": "description1",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field2",
"Description": "description2",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field3",
"Description": "description3",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field4",
"Description": "description4",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field5",
"Description": "description5",
"Mode": "NULLABLE",
"Type": "RECORD",
,
"Field": "nest1",
"Description": "description6",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest2",
"Description": "description7",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest3",
"Description": "description8",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest4",
"Description": "description9",
"Mode": "NULLABLE",
"Type": "RECORD",
,
"Field": "nest1",
"Description": "description10",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest2",
"Description": "description11",
"Mode": "NULLABLE",
"Type": "STR"
]
"table2": [
"Field": "field1",
"Description": "description1",
"Mode": "NULLABLE",
"Type": "STR"
]
（对于上下文，这旨在作为 BigQuery json 架构着陆）
【问题讨论】：
【参考方案1】：这应该可以实现您的目标：
from collections import defaultdict
d = defaultdict(list)
for t in table_list:
field_list = d[t['Table']]
field = t['Field'].split('.')
for f in field[:-1]:
field_list = next(el['Fields'] for el in field_list if el['Field'] == f)
new_d = 'Field': field[-1], 'Description': t['Description'], 'Mode': 'NULLABLE' if t['Type'] == 'STR' else 'REPEATED', 'Type': t['Type']
field_list.append(defaultdict(list, new_d))
print(json.dumps(d, indent=4))
或者如果您不想使用defaultdict：
d =
for t in table_list:
if t['Table'] not in d:
d[t['Table']] = []
field_list = d[t['Table']]
field = t['Field'].split('.')
for f in field[:-1]:
inner = next(el for el in field_list if el['Field'] == f)
if 'Fields' not in inner:
inner['Fields'] = []
field_list = inner['Fields']
new_d = 'Field': field[-1], 'Description': t['Description'], 'Mode': 'NULLABLE' if t['Type'] == 'STR' else 'REPEATED', 'Type': t['Type']
field_list.append(new_d)
输出：
"table1": [
"Field": "field1",
"Description": "description1",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field2",
"Description": "description2",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field3",
"Description": "description3",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field4",
"Description": "description4",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "field5",
"Description": "description5",
"Mode": "REPEATED",
"Type": "RECORD",
"Fields": [
"Field": "nest1",
"Description": "description6",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest2",
"Description": "description7",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest3",
"Description": "description8",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest4",
"Description": "description9",
"Mode": "REPEATED",
"Type": "RECORD",
"Fields": [
"Field": "nest1",
"Description": "description10",
"Mode": "NULLABLE",
"Type": "STR"
,
"Field": "nest2",
"Description": "description11",
"Mode": "NULLABLE",
"Type": "STR"
]
]
],
"table2": [
"Field": "field1",
"Description": "description1",
"Mode": "NULLABLE",
"Type": "STR"
]
【讨论】：
太棒了！以前从未使用过 defaultdict，但我已经爱上了它！以上是关于从字典列表中创建嵌套的 json 对象的主要内容，如果未能解决你的问题，请参考以下文章