尝试在sklearn管道上运行GridSearchCV时出错

Question

我试图通过GridSearchCV运行带有TFIDF矢量器和XGBoost分类器的sklearn管道，但由于内部错误，它无法工作。数据是4000个句子，标记为真或假（1或0）。代码如下：

import numpy as np
import pandas as pd

from gensim import utils
import gensim.parsing.preprocessing as gsp

from sklearn.pipeline import Pipeline
from sklearn.base import BaseEstimator

from sklearn.feature_extraction.text import TfidfVectorizer

import xgboost as xgb

from sklearn.model_selection import GridSearchCV
from sklearn.metrics import f1_score

train = pd.read_csv("train_data.csv")
test = pd.read_csv("test_data.csv")
train_x = train.iloc[:, 0]
train_y = train.iloc[:, 1]

test_x = test.iloc[:, 0]
test_y = test.iloc[:, 1]

folds = 4

xgb_parameters = {
                'xgboost__n_estimators': [1000, 1500],
                'xgboost__max_depth': [12, 15],
                'xgboost__learning_rate': [0.1, 0.12],
                'xgboost__objective': ['binary:logistic']
}

model = Pipeline(steps=[('tfidf', TfidfVectorizer()),
                         ('xgboost', xgb.XGBClassifier())])

gs_cv = GridSearchCV(estimator=model,
                     param_grid=xgb_parameters,
                     n_jobs=1,
                     refit=True,
                     cv=2,
                     scoring=f1_score)
gs_cv.fit(train_x, train_y)

但我得到了一个错误：

>>> gs_cv.fit(train_x, train_y)
C:\Users\draga\miniconda3\lib\site-packages\xgboost\sklearn.py:888: UserWarning: The use of label encoder in XGBClassifier is deprecated and will be removed in a future release. To remove this warning, do the following: 1) Pass option use_label_encoder=False when constructing XGBClassifier object; and 2) Encode your labels (y) as integers starting with 0, i.e. 0, 1, 2, ..., [num_class - 1].
[21:31:18] WARNING: C:/Users/Administrator/workspace/xgboost-win64_release_1.3.0/src/learner.cc:1061: Starting in XGBoost 1.3.0, the default evaluation metric used with the objective 'binary:logistic' was changed from 'error' to 'logloss'. Explicitly set eval_metric if you'd like to restore the old behavior.
C:\Users\draga\miniconda3\lib\site-packages\sklearn\utils\validation.py:70: FutureWarning: Pass labels=0       0
1       1
2       1
3       0
4       1
       ..
2004    0
2005    0
2008    0
2009    0
2012    0
Name: Bad Sentence, Length: 2000, dtype: int64 as keyword args. From version 1.0 (renaming of 0.25) passing these as positional arguments will result in an error       
  warnings.warn(f"Pass {args_msg} as keyword args. From version "
C:\Users\draga\miniconda3\lib\site-packages\sklearn\model_selection\_validation.py:683: UserWarning: Scoring failed. The score on this train-test partition for these parameters will be set to nan. Details:
Traceback (most recent call last):
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\model_selection\_validation.py", line 674, in _score
    scores = scorer(estimator, X_test, y_test)
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\utils\validation.py", line 74, in inner_f
    return f(**kwargs)
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\metrics\_classification.py", line 1068, in f1_score
    return fbeta_score(y_true, y_pred, beta=1, labels=labels,
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\utils\validation.py", line 63, in inner_f
    return f(*args, **kwargs)
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\metrics\_classification.py", line 1192, in fbeta_score
    _, _, f, _ = precision_recall_fscore_support(y_true, y_pred,
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\utils\validation.py", line 63, in inner_f
    return f(*args, **kwargs)
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\metrics\_classification.py", line 1461, in precision_recall_fscore_support
    labels = _check_set_wise_labels(y_true, y_pred, average, labels,
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\metrics\_classification.py", line 1274, in _check_set_wise_labels
    y_type, y_true, y_pred = _check_targets(y_true, y_pred)
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\metrics\_classification.py", line 83, in _check_targets
    check_consistent_length(y_true, y_pred)
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\utils\validation.py", line 259, in check_consistent_length
    lengths = [_num_samples(X) for X in arrays if X is not None]
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\utils\validation.py", line 259, in <listcomp>
    lengths = [_num_samples(X) for X in arrays if X is not None]
  File "C:\Users\draga\miniconda3\lib\site-packages\sklearn\utils\validation.py", line 192, in _num_samples
    raise TypeError(message)
TypeError: Expected sequence or array-like, got <class 'sklearn.pipeline.Pipeline'> 

1. 有什么问题吗

2. 我是否需要在管道中包含TfidfVectorizer()的转换方法

Answer 1

主要问题是搜索的scoring参数。sklearn中超参数调谐器的记分器需要有签名(estimator, X, y)。您可以使用make_scorer便利函数，或者在本例中，只需将名称作为字符串传递scorer="f1"

见文件the list of builtins和information on signatures

（您不需要显式使用transform方法；该方法由管道内部处理。）