Traktor/myenv/Lib/site-packages/sklearn/utils/_set_output.py
2024-05-26 05:12:46 +02:00

460 lines
14 KiB
Python

import importlib
from functools import wraps
from typing import Protocol, runtime_checkable
import numpy as np
from scipy.sparse import issparse
from .._config import get_config
from ._available_if import available_if
def check_library_installed(library):
"""Check library is installed."""
try:
return importlib.import_module(library)
except ImportError as exc:
raise ImportError(
f"Setting output container to '{library}' requires {library} to be"
" installed"
) from exc
def get_columns(columns):
if callable(columns):
try:
return columns()
except Exception:
return None
return columns
@runtime_checkable
class ContainerAdapterProtocol(Protocol):
container_lib: str
def create_container(self, X_output, X_original, columns, inplace=False):
"""Create container from `X_output` with additional metadata.
Parameters
----------
X_output : {ndarray, dataframe}
Data to wrap.
X_original : {ndarray, dataframe}
Original input dataframe. This is used to extract the metadata that should
be passed to `X_output`, e.g. pandas row index.
columns : callable, ndarray, or None
The column names or a callable that returns the column names. The
callable is useful if the column names require some computation. If `None`,
then no columns are passed to the container's constructor.
inplace : bool, default=False
Whether or not we intend to modify `X_output` in-place. However, it does
not guarantee that we return the same object if the in-place operation
is not possible.
Returns
-------
wrapped_output : container_type
`X_output` wrapped into the container type.
"""
def is_supported_container(self, X):
"""Return True if X is a supported container.
Parameters
----------
Xs: container
Containers to be checked.
Returns
-------
is_supported_container : bool
True if X is a supported container.
"""
def rename_columns(self, X, columns):
"""Rename columns in `X`.
Parameters
----------
X : container
Container which columns is updated.
columns : ndarray of str
Columns to update the `X`'s columns with.
Returns
-------
updated_container : container
Container with new names.
"""
def hstack(self, Xs):
"""Stack containers horizontally (column-wise).
Parameters
----------
Xs : list of containers
List of containers to stack.
Returns
-------
stacked_Xs : container
Stacked containers.
"""
class PandasAdapter:
container_lib = "pandas"
def create_container(self, X_output, X_original, columns, inplace=True):
pd = check_library_installed("pandas")
columns = get_columns(columns)
if not inplace or not isinstance(X_output, pd.DataFrame):
# In all these cases, we need to create a new DataFrame
# Unfortunately, we cannot use `getattr(container, "index")`
# because `list` exposes an `index` attribute.
if isinstance(X_output, pd.DataFrame):
index = X_output.index
elif isinstance(X_original, pd.DataFrame):
index = X_original.index
else:
index = None
# We don't pass columns here because it would intend columns selection
# instead of renaming.
X_output = pd.DataFrame(X_output, index=index, copy=not inplace)
if columns is not None:
return self.rename_columns(X_output, columns)
return X_output
def is_supported_container(self, X):
pd = check_library_installed("pandas")
return isinstance(X, pd.DataFrame)
def rename_columns(self, X, columns):
# we cannot use `rename` since it takes a dictionary and at this stage we have
# potentially duplicate column names in `X`
X.columns = columns
return X
def hstack(self, Xs):
pd = check_library_installed("pandas")
return pd.concat(Xs, axis=1)
class PolarsAdapter:
container_lib = "polars"
def create_container(self, X_output, X_original, columns, inplace=True):
pl = check_library_installed("polars")
columns = get_columns(columns)
columns = columns.tolist() if isinstance(columns, np.ndarray) else columns
if not inplace or not isinstance(X_output, pl.DataFrame):
# In all these cases, we need to create a new DataFrame
return pl.DataFrame(X_output, schema=columns, orient="row")
if columns is not None:
return self.rename_columns(X_output, columns)
return X_output
def is_supported_container(self, X):
pl = check_library_installed("polars")
return isinstance(X, pl.DataFrame)
def rename_columns(self, X, columns):
# we cannot use `rename` since it takes a dictionary and at this stage we have
# potentially duplicate column names in `X`
X.columns = columns
return X
def hstack(self, Xs):
pl = check_library_installed("polars")
return pl.concat(Xs, how="horizontal")
class ContainerAdaptersManager:
def __init__(self):
self.adapters = {}
@property
def supported_outputs(self):
return {"default"} | set(self.adapters)
def register(self, adapter):
self.adapters[adapter.container_lib] = adapter
ADAPTERS_MANAGER = ContainerAdaptersManager()
ADAPTERS_MANAGER.register(PandasAdapter())
ADAPTERS_MANAGER.register(PolarsAdapter())
def _get_adapter_from_container(container):
"""Get the adapter that knows how to handle such container.
See :class:`sklearn.utils._set_output.ContainerAdapterProtocol` for more
details.
"""
module_name = container.__class__.__module__.split(".")[0]
try:
return ADAPTERS_MANAGER.adapters[module_name]
except KeyError as exc:
available_adapters = list(ADAPTERS_MANAGER.adapters.keys())
raise ValueError(
"The container does not have a registered adapter in scikit-learn. "
f"Available adapters are: {available_adapters} while the container "
f"provided is: {container!r}."
) from exc
def _get_container_adapter(method, estimator=None):
"""Get container adapter."""
dense_config = _get_output_config(method, estimator)["dense"]
try:
return ADAPTERS_MANAGER.adapters[dense_config]
except KeyError:
return None
def _get_output_config(method, estimator=None):
"""Get output config based on estimator and global configuration.
Parameters
----------
method : {"transform"}
Estimator's method for which the output container is looked up.
estimator : estimator instance or None
Estimator to get the output configuration from. If `None`, check global
configuration is used.
Returns
-------
config : dict
Dictionary with keys:
- "dense": specifies the dense container for `method`. This can be
`"default"` or `"pandas"`.
"""
est_sklearn_output_config = getattr(estimator, "_sklearn_output_config", {})
if method in est_sklearn_output_config:
dense_config = est_sklearn_output_config[method]
else:
dense_config = get_config()[f"{method}_output"]
supported_outputs = ADAPTERS_MANAGER.supported_outputs
if dense_config not in supported_outputs:
raise ValueError(
f"output config must be in {sorted(supported_outputs)}, got {dense_config}"
)
return {"dense": dense_config}
def _wrap_data_with_container(method, data_to_wrap, original_input, estimator):
"""Wrap output with container based on an estimator's or global config.
Parameters
----------
method : {"transform"}
Estimator's method to get container output for.
data_to_wrap : {ndarray, dataframe}
Data to wrap with container.
original_input : {ndarray, dataframe}
Original input of function.
estimator : estimator instance
Estimator with to get the output configuration from.
Returns
-------
output : {ndarray, dataframe}
If the output config is "default" or the estimator is not configured
for wrapping return `data_to_wrap` unchanged.
If the output config is "pandas", return `data_to_wrap` as a pandas
DataFrame.
"""
output_config = _get_output_config(method, estimator)
if output_config["dense"] == "default" or not _auto_wrap_is_configured(estimator):
return data_to_wrap
dense_config = output_config["dense"]
if issparse(data_to_wrap):
raise ValueError(
"The transformer outputs a scipy sparse matrix. "
"Try to set the transformer output to a dense array or disable "
f"{dense_config.capitalize()} output with set_output(transform='default')."
)
adapter = ADAPTERS_MANAGER.adapters[dense_config]
return adapter.create_container(
data_to_wrap,
original_input,
columns=estimator.get_feature_names_out,
)
def _wrap_method_output(f, method):
"""Wrapper used by `_SetOutputMixin` to automatically wrap methods."""
@wraps(f)
def wrapped(self, X, *args, **kwargs):
data_to_wrap = f(self, X, *args, **kwargs)
if isinstance(data_to_wrap, tuple):
# only wrap the first output for cross decomposition
return_tuple = (
_wrap_data_with_container(method, data_to_wrap[0], X, self),
*data_to_wrap[1:],
)
# Support for namedtuples `_make` is a documented API for namedtuples:
# https://docs.python.org/3/library/collections.html#collections.somenamedtuple._make
if hasattr(type(data_to_wrap), "_make"):
return type(data_to_wrap)._make(return_tuple)
return return_tuple
return _wrap_data_with_container(method, data_to_wrap, X, self)
return wrapped
def _auto_wrap_is_configured(estimator):
"""Return True if estimator is configured for auto-wrapping the transform method.
`_SetOutputMixin` sets `_sklearn_auto_wrap_output_keys` to `set()` if auto wrapping
is manually disabled.
"""
auto_wrap_output_keys = getattr(estimator, "_sklearn_auto_wrap_output_keys", set())
return (
hasattr(estimator, "get_feature_names_out")
and "transform" in auto_wrap_output_keys
)
class _SetOutputMixin:
"""Mixin that dynamically wraps methods to return container based on config.
Currently `_SetOutputMixin` wraps `transform` and `fit_transform` and configures
it based on `set_output` of the global configuration.
`set_output` is only defined if `get_feature_names_out` is defined and
`auto_wrap_output_keys` is the default value.
"""
def __init_subclass__(cls, auto_wrap_output_keys=("transform",), **kwargs):
super().__init_subclass__(**kwargs)
# Dynamically wraps `transform` and `fit_transform` and configure it's
# output based on `set_output`.
if not (
isinstance(auto_wrap_output_keys, tuple) or auto_wrap_output_keys is None
):
raise ValueError("auto_wrap_output_keys must be None or a tuple of keys.")
if auto_wrap_output_keys is None:
cls._sklearn_auto_wrap_output_keys = set()
return
# Mapping from method to key in configurations
method_to_key = {
"transform": "transform",
"fit_transform": "transform",
}
cls._sklearn_auto_wrap_output_keys = set()
for method, key in method_to_key.items():
if not hasattr(cls, method) or key not in auto_wrap_output_keys:
continue
cls._sklearn_auto_wrap_output_keys.add(key)
# Only wrap methods defined by cls itself
if method not in cls.__dict__:
continue
wrapped_method = _wrap_method_output(getattr(cls, method), key)
setattr(cls, method, wrapped_method)
@available_if(_auto_wrap_is_configured)
def set_output(self, *, transform=None):
"""Set output container.
See :ref:`sphx_glr_auto_examples_miscellaneous_plot_set_output.py`
for an example on how to use the API.
Parameters
----------
transform : {"default", "pandas", "polars"}, default=None
Configure output of `transform` and `fit_transform`.
- `"default"`: Default output format of a transformer
- `"pandas"`: DataFrame output
- `"polars"`: Polars output
- `None`: Transform configuration is unchanged
.. versionadded:: 1.4
`"polars"` option was added.
Returns
-------
self : estimator instance
Estimator instance.
"""
if transform is None:
return self
if not hasattr(self, "_sklearn_output_config"):
self._sklearn_output_config = {}
self._sklearn_output_config["transform"] = transform
return self
def _safe_set_output(estimator, *, transform=None):
"""Safely call estimator.set_output and error if it not available.
This is used by meta-estimators to set the output for child estimators.
Parameters
----------
estimator : estimator instance
Estimator instance.
transform : {"default", "pandas", "polars"}, default=None
Configure output of the following estimator's methods:
- `"transform"`
- `"fit_transform"`
If `None`, this operation is a no-op.
Returns
-------
estimator : estimator instance
Estimator instance.
"""
set_output_for_transform = (
hasattr(estimator, "transform")
or hasattr(estimator, "fit_transform")
and transform is not None
)
if not set_output_for_transform:
# If estimator can not transform, then `set_output` does not need to be
# called.
return
if not hasattr(estimator, "set_output"):
raise ValueError(
f"Unable to configure output for {estimator} because `set_output` "
"is not available."
)
return estimator.set_output(transform=transform)