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2026-07-13 12:49:22 +08:00

213 lines
7.7 KiB
Python

"""
Checks to ensure valid inputs for various methods.
"""
from cleanlab.typing import LabelLike, DatasetLike
from cleanlab.internal.constants import FLOATING_POINT_COMPARISON
from typing import Any, List, Optional, Union
import warnings
import numpy as np
import pandas as pd
def assert_valid_inputs(
X: DatasetLike,
y: LabelLike,
pred_probs: Optional[np.ndarray] = None,
multi_label: bool = False,
allow_missing_classes: bool = True,
allow_one_class: bool = False,
) -> None:
"""Checks that ``X``, ``labels``, ``pred_probs`` are correctly formatted."""
if not isinstance(y, (list, np.ndarray, np.generic, pd.Series, pd.DataFrame)):
raise TypeError("labels should be a numpy array or pandas Series.")
if not multi_label:
y = labels_to_array(y)
assert_valid_class_labels(
y=y, allow_missing_classes=allow_missing_classes, allow_one_class=allow_one_class
)
allow_empty_X = True
if pred_probs is None:
allow_empty_X = False
if not allow_empty_X:
assert_nonempty_input(X)
try:
num_examples = len(X)
len_supported = True
except:
len_supported = False
if not len_supported:
try:
num_examples = X.shape[0]
shape_supported = True
except:
shape_supported = False
if (not len_supported) and (not shape_supported):
raise TypeError("Data features X must support either: len(X) or X.shape[0]")
if num_examples != len(y):
raise ValueError(
f"X and labels must be same length, but X is length {num_examples} and labels is length {len(y)}."
)
assert_indexing_works(X, length_X=num_examples)
if pred_probs is not None:
if not isinstance(pred_probs, (np.ndarray, np.generic)):
raise TypeError("pred_probs must be a numpy array.")
if len(pred_probs) != len(y):
raise ValueError("pred_probs and labels must have same length.")
if len(pred_probs.shape) != 2:
raise ValueError("pred_probs array must have shape: num_examples x num_classes.")
if not multi_label:
assert isinstance(y, np.ndarray)
highest_class = max(y) + 1
else:
assert isinstance(y, list)
assert all(isinstance(y_i, list) for y_i in y)
highest_class = max([max(y_i) for y_i in y if len(y_i) != 0]) + 1
if pred_probs.shape[1] < highest_class:
raise ValueError(
f"pred_probs must have at least {highest_class} columns, based on the largest class index which appears in labels."
)
# Check for valid probabilities.
if (np.min(pred_probs) < 0 - FLOATING_POINT_COMPARISON) or (
np.max(pred_probs) > 1 + FLOATING_POINT_COMPARISON
):
raise ValueError("Values in pred_probs must be between 0 and 1.")
if X is not None:
warnings.warn("When X and pred_probs are both provided, the former may be ignored.")
def assert_valid_class_labels(
y: np.ndarray,
allow_missing_classes: bool = True,
allow_one_class: bool = False,
) -> None:
"""Checks that ``labels`` is properly formatted, i.e. a 1D numpy array where labels are zero-based
integers (not multi-label).
"""
if y.ndim != 1:
raise ValueError("Labels must be 1D numpy array.")
if any([isinstance(label, str) for label in y]):
raise ValueError(
"Labels cannot be strings, they must be zero-indexed integers corresponding to class indices."
)
if not np.equal(np.mod(y, 1), 0).all(): # check that labels are integers
raise ValueError("Labels must be zero-indexed integers corresponding to class indices.")
if min(y) < 0:
raise ValueError("Labels must be positive integers corresponding to class indices.")
unique_classes = np.unique(y)
if (not allow_one_class) and (len(unique_classes) < 2):
raise ValueError("Labels must contain at least 2 classes.")
if not allow_missing_classes:
if (unique_classes != np.arange(len(unique_classes))).any():
msg = "cleanlab requires zero-indexed integer labels (0,1,2,..,K-1), but in "
msg += "your case: np.unique(labels) = {}. ".format(str(unique_classes))
msg += "Every class in (0,1,2,..,K-1) must be present in labels as well."
raise TypeError(msg)
def assert_nonempty_input(X: Any) -> None:
"""Ensures input is not None."""
if X is None:
raise ValueError("Data features X cannot be None. Currently X is None.")
def assert_indexing_works(
X: DatasetLike, idx: Optional[List[int]] = None, length_X: Optional[int] = None
) -> None:
"""Ensures we can do list-based indexing into ``X`` and ``y``.
``length_X`` is an optional argument since sparse matrix ``X``
does not support: ``len(X)`` and we want this method to work for sparse ``X``
(in addition to many other types of ``X``).
"""
if idx is None:
if length_X is None:
length_X = 2 # pragma: no cover
idx = [0, length_X - 1]
is_indexed = False
try:
if isinstance(X, (pd.DataFrame, pd.Series)):
_ = X.iloc[idx] # type: ignore[call-overload]
is_indexed = True
except Exception:
pass
if not is_indexed:
try: # check if X is pytorch Dataset object using lazy import
import torch
if isinstance(X, torch.utils.data.Dataset): # indexing for pytorch Dataset
_ = torch.utils.data.Subset(X, idx) # type: ignore[call-overload]
is_indexed = True
except Exception:
pass
if not is_indexed:
try:
_ = X[idx] # type: ignore[call-overload]
except Exception:
msg = (
"Data features X must support list-based indexing; i.e. one of these must work: \n"
)
msg += "1) X[index_list] where say index_list = [0,1,3,10], or \n"
msg += "2) X.iloc[index_list] if X is pandas DataFrame."
raise TypeError(msg)
def labels_to_array(y: Union[LabelLike, np.generic]) -> np.ndarray:
"""Converts different types of label objects to 1D numpy array and checks their validity.
Parameters
----------
y : Union[LabelLike, np.generic]
Labels to convert to 1D numpy array. Can be a list, numpy array, pandas Series, or pandas DataFrame.
Returns
-------
labels_array : np.ndarray
1D numpy array of labels.
"""
if isinstance(y, pd.Series):
y_series: np.ndarray = y.to_numpy()
return y_series
elif isinstance(y, pd.DataFrame):
y_arr = y.values
assert isinstance(y_arr, np.ndarray)
if y_arr.shape[1] != 1:
raise ValueError("labels must be one dimensional.")
return y_arr.flatten()
else: # y is list, np.ndarray, or some other tuple-like object
try:
return np.asarray(y)
except:
raise ValueError(
"List of labels must be convertable to 1D numpy array via: np.ndarray(labels)."
)
def labels_to_list_multilabel(y: List) -> List[List[int]]:
"""Converts different types of label objects to nested list and checks their validity.
Parameters
----------
y : List
Labels to convert to nested list. Supports only list type.
Returns
-------
labels_list : List[List[int]]
Nested list of labels.
"""
if not isinstance(y, list):
raise ValueError("Unsupported Label format")
if not all(isinstance(x, list) for x in y):
raise ValueError("Each element in list of labels must be a list.")
return y