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sklearn自定义pipeline的数据处理

news 来源：原创 2025/5/10 6:59:50

将自定义的频数编码处理整合到sklearn的pipeline流程里面：

from sklearn.base import BaseEstimator, TransformerMixin
from sklearn.pipeline import make_pipeline, Pipeline
from sklearn.impute import SimpleImputer
from sklearn.preprocessing import PolynomialFeatures # 多项式
from sklearn.metrics import confusion_matrix, classification_report, roc_auc_score
import lightgbm as lgbimport pandas as pddef load_data(path):data = pd.read_csv(path,usecols=lambda col: col != 'id')data['subscribe'] = data['subscribe'].apply(lambda x: 1 if x == 'yes' else 0,)return data# 自定义转换器1 将类别特征按频次编码
class Freqencode(BaseEstimator, TransformerMixin):def __init__(self, cat_cols=[]):self.cat_cols = cat_cols# 返回对象本身def fit(self, X, y=None):# 计算统计量return self# 转换数据def transform(self, X):# 数据转换逻辑for col in self.cat_cols:freq = X[col].value_counts(normalize=True).to_dict()X[col] = X[col].map(freq)return Xdef pipeline_model(cat_cols):pip_model = Pipeline(steps=[('freq_encode', Freqencode(cat_cols=cat_cols)),('imputer', SimpleImputer(strategy='mean')),('poly', PolynomialFeatures(degree=2, interaction_only=False, include_bias=False)),('model', lgb.LGBMClassifier(verbose=-1)),])return pip_modelif __name__ == '__main__':path = r"C:\Users\12048\Desktop\python_code\data\train.csv"data = load_data(path)# 类别特征cat_cols = list(data.select_dtypes(include=['object']).columns)x, y = data.drop(labels='subscribe', axis=1), data['subscribe']pip_model = pipeline_model(cat_cols)pip_model.fit(x, y)print('训练集表现：')prob = pip_model.predict_proba(x)[:,1]train_pred = [1 if i>0.5 else 0 for i in prob]print('混淆矩阵：\n',confusion_matrix(y, train_pred))print('模型报告：\n',classification_report(y, train_pred))print('auc：',roc_auc_score(y, prob))