import json
from os import PathLike
from pathlib import Path
from typing import Any, Callable, Dict, Iterator, Optional, Union
from langchain_core.documents import Document
from langchain_community.document_loaders.base import BaseLoader
[docs]
class JSONLoader(BaseLoader):
"""
Load a `JSON` file using a `jq` schema.
Setup:
.. code-block:: bash
pip install -U jq
Instantiate:
.. code-block:: python
from langchain_community.document_loaders import JSONLoader
import json
from pathlib import Path
file_path='./sample_quiz.json'
data = json.loads(Path(file_path).read_text())
loader = JSONLoader(
file_path=file_path,
jq_schema='.quiz',
text_content=False)
Load:
.. code-block:: python
docs = loader.load()
print(docs[0].page_content[:100])
print(docs[0].metadata)
.. code-block:: python
{"sport": {"q1": {"question": "Which one is correct team name in
NBA?", "options": ["New York Bulls"
{'source': '/sample_quiz
.json', 'seq_num': 1}
Async load:
.. code-block:: python
docs = await loader.aload()
print(docs[0].page_content[:100])
print(docs[0].metadata)
.. code-block:: python
{"sport": {"q1": {"question": "Which one is correct team name in
NBA?", "options": ["New York Bulls"
{'source': '/sample_quizg
.json', 'seq_num': 1}
Lazy load:
.. code-block:: python
docs = []
docs_lazy = loader.lazy_load()
# async variant:
# docs_lazy = await loader.alazy_load()
for doc in docs_lazy:
docs.append(doc)
print(docs[0].page_content[:100])
print(docs[0].metadata)
.. code-block:: python
{"sport": {"q1": {"question": "Which one is correct team name in
NBA?", "options": ["New York Bulls"
{'source': '/sample_quiz
.json', 'seq_num': 1}
"""
[docs]
def __init__(
self,
file_path: Union[str, PathLike],
jq_schema: str,
content_key: Optional[str] = None,
is_content_key_jq_parsable: Optional[bool] = False,
metadata_func: Optional[Callable[[Dict, Dict], Dict]] = None,
text_content: bool = True,
json_lines: bool = False,
):
"""Initialize the JSONLoader.
Args:
file_path (Union[str, PathLike]): The path to the JSON or JSON Lines file.
jq_schema (str): The jq schema to use to extract the data or text from
the JSON.
content_key (str): The key to use to extract the content from
the JSON if the jq_schema results to a list of objects (dict).
If is_content_key_jq_parsable is True, this has to be a jq compatible
schema. If is_content_key_jq_parsable is False, this should be a simple
string key.
is_content_key_jq_parsable (bool): A flag to determine if
content_key is parsable by jq or not. If True, content_key is
treated as a jq schema and compiled accordingly. If False or if
content_key is None, content_key is used as a simple string.
Default is False.
metadata_func (Callable[Dict, Dict]): A function that takes in the JSON
object extracted by the jq_schema and the default metadata and returns
a dict of the updated metadata.
text_content (bool): Boolean flag to indicate whether the content is in
string format, default to True.
json_lines (bool): Boolean flag to indicate whether the input is in
JSON Lines format.
"""
try:
import jq
self.jq = jq
except ImportError:
raise ImportError(
"jq package not found, please install it with `pip install jq`"
)
self.file_path = Path(file_path).resolve()
self._jq_schema = jq.compile(jq_schema)
self._is_content_key_jq_parsable = is_content_key_jq_parsable
self._content_key = content_key
self._metadata_func = metadata_func
self._text_content = text_content
self._json_lines = json_lines
[docs]
def lazy_load(self) -> Iterator[Document]:
"""Load and return documents from the JSON file."""
index = 0
if self._json_lines:
with self.file_path.open(encoding="utf-8") as f:
for line in f:
line = line.strip()
if line:
for doc in self._parse(line, index):
yield doc
index += 1
else:
for doc in self._parse(self.file_path.read_text(encoding="utf-8"), index):
yield doc
index += 1
def _parse(self, content: str, index: int) -> Iterator[Document]:
"""Convert given content to documents."""
data = self._jq_schema.input(json.loads(content))
# Perform some validation
# This is not a perfect validation, but it should catch most cases
# and prevent the user from getting a cryptic error later on.
if self._content_key is not None:
self._validate_content_key(data)
if self._metadata_func is not None:
self._validate_metadata_func(data)
for i, sample in enumerate(data, index + 1):
text = self._get_text(sample=sample)
metadata = self._get_metadata(
sample=sample, source=str(self.file_path), seq_num=i
)
yield Document(page_content=text, metadata=metadata)
def _get_text(self, sample: Any) -> str:
"""Convert sample to string format"""
if self._content_key is not None:
if self._is_content_key_jq_parsable:
compiled_content_key = self.jq.compile(self._content_key)
content = compiled_content_key.input(sample).first()
else:
content = sample[self._content_key]
else:
content = sample
if self._text_content and not isinstance(content, str):
raise ValueError(
f"Expected page_content is string, got {type(content)} instead. \
Set `text_content=False` if the desired input for \
`page_content` is not a string"
)
# In case the text is None, set it to an empty string
elif isinstance(content, str):
return content
elif isinstance(content, dict):
return json.dumps(content) if content else ""
else:
return str(content) if content is not None else ""
def _get_metadata(
self, sample: Dict[str, Any], **additional_fields: Any
) -> Dict[str, Any]:
"""
Return a metadata dictionary base on the existence of metadata_func
:param sample: single data payload
:param additional_fields: key-word arguments to be added as metadata values
:return:
"""
if self._metadata_func is not None:
return self._metadata_func(sample, additional_fields)
else:
return additional_fields
def _validate_content_key(self, data: Any) -> None:
"""Check if a content key is valid"""
sample = data.first()
if not isinstance(sample, dict):
raise ValueError(
f"Expected the jq schema to result in a list of objects (dict), \
so sample must be a dict but got `{type(sample)}`"
)
if (
not self._is_content_key_jq_parsable
and sample.get(self._content_key) is None
):
raise ValueError(
f"Expected the jq schema to result in a list of objects (dict) \
with the key `{self._content_key}`"
)
if (
self._is_content_key_jq_parsable
and self.jq.compile(self._content_key).input(sample).text() is None
):
raise ValueError(
f"Expected the jq schema to result in a list of objects (dict) \
with the key `{self._content_key}` which should be parsable by jq"
)
def _validate_metadata_func(self, data: Any) -> None:
"""Check if the metadata_func output is valid"""
sample = data.first()
if self._metadata_func is not None:
sample_metadata = self._metadata_func(sample, {})
if not isinstance(sample_metadata, dict):
raise ValueError(
f"Expected the metadata_func to return a dict but got \
`{type(sample_metadata)}`"
)
