LocalFileStore#

class langchain.storage.file_system.LocalFileStore(root_path: str | Path, *, chmod_file: int | None = None, chmod_dir: int | None = None, update_atime: bool = False)[source]#

BaseStore interface that works on the local file system.

Examples

Create a LocalFileStore instance and perform operations on it:

from langchain.storage import LocalFileStore

# Instantiate the LocalFileStore with the root path
file_store = LocalFileStore("/path/to/root")

# Set values for keys
file_store.mset([("key1", b"value1"), ("key2", b"value2")])

# Get values for keys
values = file_store.mget(["key1", "key2"])  # Returns [b"value1", b"value2"]

# Delete keys
file_store.mdelete(["key1"])

# Iterate over keys
for key in file_store.yield_keys():
    print(key)  # noqa: T201

Implement the BaseStore interface for the local file system.

Parameters:

root_path (Union[str, Path]) – The root path of the file store. All keys are interpreted as paths relative to this root.
chmod_file (int | None) – (optional, defaults to None) If specified, sets permissions for newly created files, overriding the current umask if needed.
chmod_dir (int | None) – (optional, defaults to None) If specified, sets permissions for newly created dirs, overriding the current umask if needed.
update_atime (bool) – (optional, defaults to False) If True, updates the filesystem access time (but not the modified time) when a file is read. This allows MRU/LRU cache policies to be implemented for filesystems where access time updates are disabled.

Methods

`__init__`(root_path, *[, chmod_file, ...])	Implement the BaseStore interface for the local file system.
`amdelete`(keys)	Async delete the given keys and their associated values.
`amget`(keys)	Async get the values associated with the given keys.
`amset`(key_value_pairs)	Async set the values for the given keys.
`ayield_keys`(*[, prefix])	Async get an iterator over keys that match the given prefix.
`mdelete`(keys)	Delete the given keys and their associated values.
`mget`(keys)	Get the values associated with the given keys.
`mset`(key_value_pairs)	Set the values for the given keys.
`yield_keys`([prefix])	Get an iterator over keys that match the given prefix.

__init__(root_path: str | Path, *, chmod_file: int | None = None, chmod_dir: int | None = None, update_atime: bool = False) → None[source]#

Implement the BaseStore interface for the local file system.

Parameters:

root_path (Union[str, Path]) – The root path of the file store. All keys are interpreted as paths relative to this root.
chmod_file (int | None) – (optional, defaults to None) If specified, sets permissions for newly created files, overriding the current umask if needed.
chmod_dir (int | None) – (optional, defaults to None) If specified, sets permissions for newly created dirs, overriding the current umask if needed.
update_atime (bool) – (optional, defaults to False) If True, updates the filesystem access time (but not the modified time) when a file is read. This allows MRU/LRU cache policies to be implemented for filesystems where access time updates are disabled.

Return type:

None

async amdelete(keys: Sequence[K]) → None#

Async delete the given keys and their associated values.

Parameters:: keys (Sequence[K]) – A sequence of keys to delete.
Return type:: None

async amget(keys: Sequence[K]) → list[V | None]#

Async get the values associated with the given keys.

Parameters:: keys (Sequence[K]) – A sequence of keys.
Returns:: A sequence of optional values associated with the keys. If a key is not found, the corresponding value will be None.
Return type:: list[V | None]

async amset(key_value_pairs: Sequence[tuple[K, V]]) → None#

Async set the values for the given keys.

Parameters:: key_value_pairs (Sequence[Tuple[K, V]]) – A sequence of key-value pairs.
Return type:: None

async ayield_keys(*, prefix: str | None = None) → AsyncIterator[K] | AsyncIterator[str]#

Async get an iterator over keys that match the given prefix.

Parameters:: prefix (str) – The prefix to match.
Yields:: Iterator[K | str] – An iterator over keys that match the given prefix. This method is allowed to return an iterator over either K or str depending on what makes more sense for the given store.
Return type:: AsyncIterator[K] | AsyncIterator[str]

mdelete(keys: Sequence[str]) → None[source]#

Delete the given keys and their associated values.

Parameters:: keys (Sequence[str]) – A sequence of keys to delete.
Returns:: None
Return type:: None

mget(keys: Sequence[str]) → List[bytes | None][source]#

Get the values associated with the given keys.

Parameters:: keys (Sequence[str]) – A sequence of keys.
Returns:: A sequence of optional values associated with the keys. If a key is not found, the corresponding value will be None.
Return type:: List[bytes | None]

mset(key_value_pairs: Sequence[Tuple[str, bytes]]) → None[source]#

Set the values for the given keys.

Parameters:: key_value_pairs (Sequence[Tuple[str, bytes]]) – A sequence of key-value pairs.
Returns:: None
Return type:: None

yield_keys(prefix: str | None = None) → Iterator[str][source]#

Get an iterator over keys that match the given prefix.

Parameters:: prefix (Optional[str]) – The prefix to match.
Returns:: An iterator over keys that match the given prefix.
Return type:: Iterator[str]

Examples using LocalFileStore