JSON
JSON (JavaScript Object Notation) 是一种开放标准的文件格式和数据交换格式，存储和传输方便，且可读。JSON 对象由属性 key - 值 value 对和数组（或其他可序列化值）组成的数据对象。
JSONLoader使用指定的 jq schema 来解析 JSON 文件。它使用jqpython 包。 查看这个 手册 来详细了解jq语法。
pip install jq
from langchain.document_loaders import JSONLoader
import json
from pathlib import Path
from pprint import pprint
file_path='./example_data/facebook_chat.json'
data = json.loads(Path(file_path).read_text())
pprint(data)
{'image': {'creation_timestamp': 1675549016, 'uri': 'image_of_the_chat.jpg'},
'is_still_participant': True,
'joinable_mode': {'link': '', 'mode': 1},
'magic_words': [],
'messages': [{'content': 'Bye!',
'sender_name': 'User 2',
'timestamp_ms': 1675597571851},
{'content': 'Oh no worries! Bye',
'sender_name': 'User 1',
'timestamp_ms': 1675597435669},
{'content': 'No Im sorry it was my mistake, the blue one is not '
'for sale',
'sender_name': 'User 2',
'timestamp_ms': 1675596277579},
{'content': 'I thought you were selling the blue one!',
'sender_name': 'User 1',
'timestamp_ms': 1675595140251},
{'content': 'Im not interested in this bag. Im interested in the '
'blue one!',
'sender_name': 'User 1',
'timestamp_ms': 1675595109305},
{'content': 'Here is $129',
'sender_name': 'User 2',
'timestamp_ms': 1675595068468},
{'photos': [{'creation_timestamp': 1675595059,
'uri': 'url_of_some_picture.jpg'}],
'sender_name': 'User 2',
'timestamp_ms': 1675595060730},
{'content': 'Online is at least $100',
'sender_name': 'User 2',
'timestamp_ms': 1675595045152},
{'content': 'How much do you want?',
'sender_name': 'User 1',
'timestamp_ms': 1675594799696},
{'content': 'Goodmorning! $50 is too low.',
'sender_name': 'User 2',
'timestamp_ms': 1675577876645},
{'content': 'Hi! Im interested in your bag. Im offering $50. Let '
'me know if you are interested. Thanks!',
'sender_name': 'User 1',
'timestamp_ms': 1675549022673}],
'participants': [{'name': 'User 1'}, {'name': 'User 2'}],
'thread_path': 'inbox/User 1 and User 2 chat',
'title': 'User 1 and User 2 chat'}
使用 JSONLoader
假设我们有兴趣提取 JSON 数据中 messages 键下的 content 字段的值。通过以下示例可以轻松完成这项工作。
loader = JSONLoader(
file_path='./example_data/facebook_chat.json',
jq_schema='.messages[].content')
data = loader.load()
pprint(data)
[Document(page_content='Bye!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 1}),
Document(page_content='Oh no worries! Bye', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 2}),
Document(page_content='No Im sorry it was my mistake, the blue one is not for sale', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 3}),
Document(page_content='I thought you were selling the blue one!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 4}),
Document(page_content='Im not interested in this bag. Im interested in the blue one!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 5}),
Document(page_content='Here is $129', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 6}),
Document(page_content='', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 7}),
Document(page_content='Online is at least $100', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 8}),
Document(page_content='How much do you want?', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 9}),
Document(page_content='Goodmorning! $50 is too low.', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 10}),
Document(page_content='Hi! Im interested in your bag. Im offering $50. Let me know if you are interested. Thanks!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 11})]
提取元数据 （Extracting metadata）
通常，我们希望将 JSON 文件中的元数据包含到从内容创建的文档中。
下面演示了如何使用 JSONLoader 提取元数据。
需要注意一些关键的更改。在前一个示例中，我们没有收集元数据，在模式中直接指定了 page_content 的值的提取位置。
.messages[].content
在当前示例中，我们必须告诉加载器迭代 messages 字段中的记录。因此，jq_schema 必须是以下形式：
.messages[]
这样我们就可以将记录（字典）传递给必须实现的 metadata_func。metadata_func 负责确定哪些记录中的信息应该包含在最终 Document 对象中的元数据中。
此外，现在我们必须通过加载器显式指定 content_key 参数，用于从记录中提取 page_content 的值的键。
Define the metadata extraction function.
def metadata_func(record: dict, metadata: dict) -> dict:
metadata["sender_name"] = record.get("sender_name")
metadata["timestamp_ms"] = record.get("timestamp_ms")
return metadata
loader = JSONLoader(
file_path='./example_data/facebook_chat.json',
jq_schema='.messages[]',
content_key="content",
metadata_func=metadata_func
)
data = loader.load()
pprint(data)
[Document(page_content='Bye!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 1, 'sender_name': 'User 2', 'timestamp_ms': 1675597571851}),
Document(page_content='Oh no worries! Bye', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 2, 'sender_name': 'User 1', 'timestamp_ms': 1675597435669}),
Document(page_content='No Im sorry it was my mistake, the blue one is not for sale', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 3, 'sender_name': 'User 2', 'timestamp_ms': 1675596277579}),
Document(page_content='I thought you were selling the blue one!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 4, 'sender_name': 'User 1', 'timestamp_ms': 1675595140251}),
Document(page_content='Im not interested in this bag. Im interested in the blue one!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 5, 'sender_name': 'User 1', 'timestamp_ms': 1675595109305}),
Document(page_content='Here is $129', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 6, 'sender_name': 'User 2', 'timestamp_ms': 1675595068468}),
Document(page_content='', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 7, 'sender_name': 'User 2', 'timestamp_ms': 1675595060730}),
Document(page_content='Online is at least $100', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 8, 'sender_name': 'User 2', 'timestamp_ms': 1675595045152}),
Document(page_content='How much do you want?', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 9, 'sender_name': 'User 1', 'timestamp_ms': 1675594799696}),
Document(page_content='Goodmorning! $50 is too low.', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 10, 'sender_name': 'User 2', 'timestamp_ms': 1675577876645}),
Document(page_content='Hi! Im interested in your bag. Im offering $50. Let me know if you are interested. Thanks!', metadata={'source': '/Users/avsolatorio/WBG/langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 11, 'sender_name': 'User 1', 'timestamp_ms': 1675549022673})]
现在，您将看到文档包含与我们提取的内容相关联的元数据。
metadata_func
如上所示，metadata_func 接受 JSONLoader 生成的默认元数据。这允许用户完全控制元数据的格式。
例如，默认元数据包含 source 和 seq_num 键。然而，JSON 数据中可能也包含这些键。用户可以利用 metadata_func 重命名默认键并使用 JSON 数据中的键。
下面的示例展示了如何修改 source，只包含与 langchain 目录相关的文件来源信息。
Define the metadata extraction function.
def metadata_func(record: dict, metadata: dict) -> dict:
metadata["sender_name"] = record.get("sender_name")
metadata["timestamp_ms"] = record.get("timestamp_ms")
if "source" in metadata:
source = metadata["source"].split("/")
source = source[source.index("langchain"):]
metadata["source"] = "/".join(source)
return metadata
loader = JSONLoader(
file_path='./example_data/facebook_chat.json',
jq_schema='.messages[]',
content_key="content",
metadata_func=metadata_func
)
data = loader.load()
pprint(data)
[Document(page_content='Bye!', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 1, 'sender_name': 'User 2', 'timestamp_ms': 1675597571851}),
Document(page_content='Oh no worries! Bye', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 2, 'sender_name': 'User 1', 'timestamp_ms': 1675597435669}),
Document(page_content='No Im sorry it was my mistake, the blue one is not for sale', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 3, 'sender_name': 'User 2', 'timestamp_ms': 1675596277579}),
Document(page_content='I thought you were selling the blue one!', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 4, 'sender_name': 'User 1', 'timestamp_ms': 1675595140251}),
Document(page_content='Im not interested in this bag. Im interested in the blue one!', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 5, 'sender_name': 'User 1', 'timestamp_ms': 1675595109305}),
Document(page_content='Here is $129', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 6, 'sender_name': 'User 2', 'timestamp_ms': 1675595068468}),
Document(page_content='', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 7, 'sender_name': 'User 2', 'timestamp_ms': 1675595060730}),
Document(page_content='Online is at least $100', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 8, 'sender_name': 'User 2', 'timestamp_ms': 1675595045152}),
Document(page_content='How much do you want?', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 9, 'sender_name': 'User 1', 'timestamp_ms': 1675594799696}),
Document(page_content='Goodmorning! $50 is too low.', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 10, 'sender_name': 'User 2', 'timestamp_ms': 1675577876645}),
Document(page_content='Hi! Im interested in your bag. Im offering $50. Let me know if you are interested. Thanks!', metadata={'source': 'langchain/docs/modules/indexes/document_loaders/examples/example_data/facebook_chat.json', 'seq_num': 11, 'sender_name': 'User 1', 'timestamp_ms': 1675549022673})]
jq schema 中常见的 JSON 结构
下面的列表提供了用户可以根据结构从 JSON 数据中提取内容时使用的可能的 jq_schema 的参考。
JSON -> [{"text": ...}, {"text": ...}, {"text": ...}]
jq_schema -> ".[].text"
JSON -> {"key": [{"text": ...}, {"text": ...}, {"text": ...}]}
jq_schema -> ".key[].text"
JSON -> ["...", "...", "..."]
jq_schema -> ".[]"