"""GenericDataset loads and saves data to a local file. The
underlying functionality is supported by geopandas, so it supports all
allowed geopandas (pandas) options for loading and saving geosjon files.
"""
from __future__ import annotations
import copy
from pathlib import PurePosixPath
from typing import Any
import fsspec
import geopandas as gpd
from kedro.io.core import (
AbstractVersionedDataset,
DatasetError,
Version,
get_filepath_str,
get_protocol_and_path,
)
# pyogrio currently supports no alternate file handlers https://github.com/geopandas/pyogrio/issues/430
gpd.options.io_engine = "fiona"
NON_FILE_SYSTEM_TARGETS = ["postgis"]
[docs]
class GenericDataset(
AbstractVersionedDataset[
gpd.GeoDataFrame, gpd.GeoDataFrame | dict[str, gpd.GeoDataFrame]
]
):
"""``GenericDataset`` loads/saves data to a file using an underlying filesystem
(eg: local, S3, GCS).
The underlying functionality is supported by geopandas, so it supports all
allowed geopandas (pandas) options for loading and saving files.
Example:
.. code-block:: pycon
>>> import geopandas as gpd
>>> from kedro_datasets.geopandas import GenericDataset
>>> from shapely.geometry import Point
>>>
>>> data = gpd.GeoDataFrame(
... {"col1": [1, 2], "col2": [4, 5], "col3": [5, 6]},
... geometry=[Point(1, 1), Point(2, 4)],
... )
>>> dataset = GenericDataset(filepath=tmp_path / "test.geojson")
>>> dataset.save(data)
>>> reloaded = dataset.load()
>>>
>>> assert data.equals(reloaded)
"""
DEFAULT_LOAD_ARGS: dict[str, Any] = {}
DEFAULT_SAVE_ARGS: dict[str, Any] = {}
DEFAULT_FS_ARGS: dict[str, Any] = {"open_args_save": {"mode": "wb"}}
[docs]
def __init__( # noqa: PLR0913
self,
*,
filepath: str,
file_format: str = "file",
load_args: dict[str, Any] | None = None,
save_args: dict[str, Any] | None = None,
version: Version | None = None,
credentials: dict[str, Any] | None = None,
fs_args: dict[str, Any] | None = None,
metadata: dict[str, Any] | None = None,
) -> None:
"""Creates a new instance of ``GenericDataset`` pointing to a concrete file
on a specific filesystem fsspec.
Args:
filepath: Filepath in POSIX format to a file prefixed with a protocol like
`s3://`. If prefix is not provided `file` protocol (local filesystem) will be used.
The prefix should be any protocol supported by ``fsspec``.
Note: `http(s)` doesn't support versioning.
file_format: String which is used to match the appropriate load/save method on a best
effort basis. For example if 'parquet' is passed in the `geopandas.read_parquet` and
`geopandas.DataFrame.to_parquet` will be identified. An error will be raised unless
at least one matching `read_{file_format}` or `to_{file_format}` method is
identified. Defaults to 'file'.
load_args: GeoPandas options for loading files.
Here you can find all available arguments:
https://geopandas.org/en/stable/docs/reference/api/geopandas.read_file.html
save_args: GeoPandas options for saving files.
Here you can find all available arguments:
https://geopandas.org/en/stable/docs/reference/api/geopandas.GeoDataFrame.to_file.html
version: If specified, should be an instance of
``kedro.io.core.Version``. If its ``load`` attribute is
None, the latest version will be loaded. If its ``save``
credentials: credentials required to access the underlying filesystem.
Eg. for ``GCFileSystem`` it would look like `{'token': None}`.
fs_args: Extra arguments to pass into underlying filesystem class constructor
(e.g. `{"project": "my-project"}` for ``GCSFileSystem``), as well as
to pass to the filesystem's `open` method through nested keys
`open_args_load` and `open_args_save`.
Here you can find all available arguments for `open`:
https://filesystem-spec.readthedocs.io/en/latest/api.html#fsspec.spec.AbstractFileSystem.open
All defaults are preserved, except `mode`, which is set to `wb` when saving.
metadata: Any arbitrary metadata.
This is ignored by Kedro, but may be consumed by users or external plugins.
"""
self._file_format = file_format.lower()
_fs_args = copy.deepcopy(fs_args) or {}
_fs_open_args_load = _fs_args.pop("open_args_load", {})
_fs_open_args_save = _fs_args.pop("open_args_save", {})
_credentials = copy.deepcopy(credentials) or {}
protocol, path = get_protocol_and_path(filepath, version)
self._protocol = protocol
if protocol == "file":
_fs_args.setdefault("auto_mkdir", True)
self._fs = fsspec.filesystem(self._protocol, **_credentials, **_fs_args)
self.metadata = metadata
super().__init__(
filepath=PurePosixPath(path),
version=version,
exists_function=self._fs.exists,
glob_function=self._fs.glob,
)
# Handle default load and save and fs arguments
self._load_args = {**self.DEFAULT_LOAD_ARGS, **(load_args or {})}
self._save_args = {**self.DEFAULT_SAVE_ARGS, **(save_args or {})}
self._fs_open_args_load = {
**self.DEFAULT_FS_ARGS.get("open_args_load", {}),
**(_fs_open_args_load or {}),
}
self._fs_open_args_save = {
**self.DEFAULT_FS_ARGS.get("open_args_save", {}),
**(_fs_open_args_save or {}),
}
def _ensure_file_system_target(self) -> None:
# Fail fast if provided a known non-filesystem target
if self._file_format in NON_FILE_SYSTEM_TARGETS:
raise DatasetError(
f"Cannot load or save a dataset of file_format '{self._file_format}' as it "
f"does not support a filepath target/source."
)
[docs]
def load(self) -> gpd.GeoDataFrame | dict[str, gpd.GeoDataFrame]:
self._ensure_file_system_target()
load_path = get_filepath_str(self._get_load_path(), self._protocol)
load_method = getattr(gpd, f"read_{self._file_format}", None)
if load_method:
with self._fs.open(load_path, **self._fs_open_args_load) as fs_file:
return load_method(fs_file, **self._load_args)
raise DatasetError(
f"Unable to retrieve 'geopandas.read_{self._file_format}' method, please ensure that your "
"'file_format' parameter has been defined correctly as per the GeoPandas API "
"https://geopandas.org/en/stable/docs/reference/io.html"
)
[docs]
def save(self, data: gpd.GeoDataFrame) -> None:
self._ensure_file_system_target()
save_path = get_filepath_str(self._get_save_path(), self._protocol)
save_method = getattr(data, f"to_{self._file_format}", None)
if save_method:
with self._fs.open(save_path, **self._fs_open_args_save) as fs_file:
# KEY ASSUMPTION - first argument is path/buffer/io
save_method(fs_file, **self._save_args)
self.invalidate_cache()
else:
raise DatasetError(
f"Unable to retrieve 'geopandas.DataFrame.to_{self._file_format}' method, please "
"ensure that your 'file_format' parameter has been defined correctly as "
"per the GeoPandas API "
"https://geopandas.org/en/stable/docs/reference/io.html"
)
def _exists(self) -> bool:
try:
load_path = get_filepath_str(self._get_load_path(), self._protocol)
except DatasetError:
return False
return self._fs.exists(load_path)
def _describe(self) -> dict[str, Any]:
return {
"filepath": self._filepath,
"file_format": self._file_format,
"protocol": self._protocol,
"load_args": self._load_args,
"save_args": self._save_args,
"version": self._version,
}
def _release(self) -> None:
self.invalidate_cache()
[docs]
def invalidate_cache(self) -> None:
"""Invalidate underlying filesystem cache."""
filepath = get_filepath_str(self._filepath, self._protocol)
self._fs.invalidate_cache(filepath)
