用户贷款违约预测-Top1方案-单模0.9414-Toy模板网

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赛题描述

用户贷款违约预测，分类任务，label是响应变量。采用AUC作为评价指标。相关字段以及解释如下。数据集质量比较高，无缺失值。由于数据都已标准化和匿名化处理，因此较难分析异常值。

字段	描述	类型
id	样本唯一标识符	已匿名处理
income	用户收入	已做标准化处理
age	用户年龄	已做标准化处理
experience_years	用户从业年限	已做标准化处理
is_married	用户是否结婚	已匿名处理
city	居住城市，匿名处理	已做标准化处理
region	居住地区，匿名处理	已做标准化处理
current_job_years	现任职位工作年限	已匿名处理
current_house_years	在现房屋的居住年数	已做标准化处理
house_ownership	房屋类型：租用；个人；未有	已做标准化处理
car_ownership	是否拥有汽车	已匿名处理
profession	职业，匿名处理	已做标准化处理
label	表示过去是否存在违约	float

特征工程

在数据科学类竞赛中，特征工程极为重要，其重要性要远大于模型和参数。

在特征工程中，主要做了以下几个方面

针对类别特征对连续特征进行分组统计，进行特征衍生。
针对收入、年龄、从业年限进行分箱
针对类别特征进行Target Encoding
~~针对样本不均衡进行处理，利用SMOTE+ENN进行采样处理（分数不升反降，猜测在采样和清洗过程中引入了噪声，丢失了信息，后没再用）~~
针对连续特征进行标准化和归一化操作
类别特征二阶组合

分组统计

# //求熵
def myEntro(x):
    """
        calculate shanno ent of x
    """
    x = np.array(x)
    x_value_list = set([x[i] for i in range(x.shape[0])])
    ent = 0.0
    for x_value in x_value_list:
        p = float(x[x == x_value].shape[0]) / x.shape[0]
        logp = np.log2(p)
        ent -= p * logp
    #     print(x_value,p,logp)
    # print(ent)
    return ent

    
# //求值的范围
def myRange(x):
    return pd.Series.max(x) - pd.Series.min(x)
    
feature = ['income', 'age', 'experience_years', 'is_married', 'city',
       'region', 'current_job_years', 'current_house_years', 'house_ownership',
       'car_ownership', 'profession']
    #    , 'current_job_years_precentage',
    #    'income_pre_age', 'income_pre_experience_years',
    #    'experience_years_pre_age']

cat_feature = ['is_married','city','region','house_ownership','car_ownership','profession']
#类别特征
num_feature = ['income', 'age', 'experience_years', 'current_job_years', 'current_house_years']#,'income_pre_age','income_pre_experience_years','experience_years_pre_age']
#连续特征
ways = ['mean','max','min','std','sum','median',myEntro,myRange]#,myRms,myMode,myQ25,myQ75,myQ10,myQ90]
#进行统计的方法

for cat in tqdm(cat_feature):
    data[cat+"_"+"count"] =  data.groupby(cat)['id'].transform('count')
    feature.append(cat+"_"+"count")

    data[cat+"_"+"label_mean"] = data.groupby(cat)['label'].transform('mean')
    feature.append(cat+"_"+"label_mean")

    for num in num_feature:
        for way in ways:
            data[num+'_'+cat+"_"+str(way)] = data.groupby(cat)[num].transform(way)
            feature.append(num+'_'+cat+"_"+str(way))

分箱

num_feature = list(set(feature) - set(cat_feature))
#分箱
for i in tqdm(['income']):
    data[i+'_cut'] = pd.cut(data[i],bins=100,labels=range(100)).astype('int')
    feature.append(i+'_cut')
    cat_feature.append(i+'_cut')

for i in tqdm(['age']):
    data[i+'_cut'] = pd.cut(data[i],bins=10,labels=range(10)).astype('int')
    feature.append(i+'_cut')
    cat_feature.append(i+'_cut')

for i in tqdm(['experience_years']):
    data[i+'_cut'] = pd.cut(data[i],bins=5,labels=range(5)).astype('int')
    feature.append(i+'_cut')
    cat_feature.append(i+'_cut')

标准化归一化

transfer = StandardScaler()
# 调用fit_transform （只需要处理连续特征）
num_feature = list(set(feature) - set(cat_feature))
data[num_feature] = transfer.fit_transform(data[num_feature])

transfer = MinMaxScaler()
data[num_feature] = transfer.fit_transform(data[num_feature])

类别特征二阶组合

enc = LabelEncoder()
num = len(cat_feature)
for i in tqdm(range(num)):
    for j in range(i,num):
        name = str(cat_feature[i])+"_"+str(cat_feature[j])
        data[name] = data[cat_feature[i]].astype(str) + data[cat_feature[j]].astype(str)
        data[name] = enc.fit_transform(data[name]) 
        feature.append(name)
        cat_feature.append(name)

模型搭建

尝试了Catboost，XGBoost，LightGBM。Catboost表现最好，且由于时间原因，未做模型融合，只使用CatBoost。

构建模型

def train_model_classification(X, X_test, y, params, num_classes=2,
                               folds=None, model_type='lgb',
                               eval_metric='logloss', columns=None,
                               plot_feature_importance=False,
                               model=None, verbose=10000,
                               early_stopping_rounds=200,
                               splits=None, n_folds=3):
    """
    分类模型函数
    返回字典，包括： oof predictions, test predictions, scores and, if necessary, feature importances.
    :params: X - 训练数据， pd.DataFrame
    :params: X_test - 测试数据，pd.DataFrame
    :params: y - 目标
    :params: folds - folds to split data
    :params: model_type - 模型
    :params: eval_metric - 评价指标
    :params: columns - 特征列
    :params: plot_feature_importance - 是否展示特征重要性
    :params: model - sklearn model, works only for "sklearn" model type
    """
    start_time = time.time()
    global y_pred_valid, y_pred

    columns = X.columns if columns is None else columns
    X_test = X_test[columns]
    splits = folds.split(X, y) if splits is None else splits
    n_splits = folds.n_splits if splits is None else n_folds

    # to set up scoring parameters
    metrics_dict = {
        'logloss': {
            'lgb_metric_name': 'logloss',
            'xgb_metric_name': 'logloss',
            'catboost_metric_name': 'Logloss',
            'sklearn_scoring_function': metrics.log_loss
        },
        'lb_score_method': {
            'sklearn_scoring_f1': metrics.f1_score,  # 线上评价指标
            'sklearn_scoring_accuracy': metrics.accuracy_score,  # 线上评价指标
            'sklearn_scoring_auc': metrics.roc_auc_score
        },
    }
    result_dict = {}
    count = 0
    # out-of-fold predictions on train data
    oof = np.zeros(shape=(len(X), num_classes))
    # averaged predictions on train data
    prediction = np.zeros(shape=(len(X_test), num_classes))
    # list of scores on folds
    acc_scores=[]
    scores = []
    # feature importance
    feature_importance = pd.DataFrame()

    # split and train on folds
    for fold_n, (train_index, valid_index) in enumerate(splits):
        if verbose:
            print(f'Fold {fold_n + 1} started at {time.ctime()}')
        if type(X) == np.ndarray:
            X_train, X_valid = X[train_index], X[valid_index]
            y_train, y_valid = y[train_index], y[valid_index]
        else:
            X_train, X_valid = X[columns].iloc[train_index], X[columns].iloc[valid_index]
            y_train, y_valid = y.iloc[train_index], y.iloc[valid_index]
        # 在此进行数据采样处理
        # print("采样处理前,正负样本比例为",Counter(y_train),end = '\t')
        # smo_enn = SMOTENC(categorical_features=[i for i in range(len(feature)) if feature[i] in cat_feature],random_state=2023,n_jobs=-1)
        # X_train, y_train = smo_enn.fit_resample(X_train, y_train)
        # print("采样处理后,正负样本比例为",Counter(y_train))

        if model_type == 'lgb':
            model = LGBMClassifier(**params)
            model.fit(X_train, y_train,
                      eval_set=[(X_train, y_train), (X_valid, y_valid)],
                      eval_metric=metrics_dict[eval_metric]['lgb_metric_name'],
                      verbose=verbose,
                      early_stopping_rounds=early_stopping_rounds)

            y_pred_valid = model.predict_proba(X_valid)
            y_pred = model.predict_proba(X_test, num_iteration=model.best_iteration_)

        if model_type == 'xgb':
            model = xgb.XGBClassifier(**params)
            model.fit(X_train, y_train,
                      eval_set=[(X_train, y_train), (X_valid, y_valid)],
                      eval_metric=metrics_dict[eval_metric]['xgb_metric_name'],
                      verbose=bool(verbose),  # xgb verbose bool
                      early_stopping_rounds=early_stopping_rounds)
            y_pred_valid = model.predict_proba(X_valid)
            y_pred = model.predict_proba(X_test, ntree_limit=model.best_ntree_limit)
        if model_type == 'sklearn':
            model = model
            model.fit(X_train, y_train)
            y_pred_valid = model.predict_proba(X_valid)
            score = metrics_dict[eval_metric]['sklearn_scoring_function'](y_valid, y_pred_valid)
            print(f'Fold {fold_n}. {eval_metric}: {score:.4f}.')
            y_pred = model.predict_proba(X_test)

        if model_type == 'cat':
            model = CatBoostClassifier(iterations=20000, eval_metric=metrics_dict[eval_metric]['catboost_metric_name'],
                                       **params,
                                       loss_function=metrics_dict[eval_metric]['catboost_metric_name'])
            model.fit(X_train, y_train, eval_set=(X_valid, y_valid), 
                        cat_features=cat_feature, 
                        # num_features = num_feature,
                        #  pairwise_interactions=origin_feature,
                        use_best_model=True,
                      verbose=False)
            # model = BalancedBaggingClassifier(base_estimator=model,
            #                     sampling_strategy='auto',
            #                     replacement=False,
            #                     random_state=0)
            # model.fit(X_train, y_train)

            y_pre_train = model.predict_proba(X_train)
            y_pred_valid = model.predict_proba(X_valid)
            y_pred = model.predict_proba(X_test)


        oof[valid_index] = y_pred_valid
        # 评价指标
        acc_scores.append(
            metrics_dict['lb_score_method']['sklearn_scoring_accuracy'](y_valid, np.argmax(y_pred_valid, axis=1)))
        scores.append(
            metrics_dict['lb_score_method']['sklearn_scoring_auc'](y_valid, y_pred_valid[:,1]))
        print(acc_scores)
        print(scores)
        # if scores[-1]>0.94:
        #     prediction += y_pred
        #     count = count+1
        prediction += y_pred
        if model_type == 'lgb' and plot_feature_importance:
            # feature importance
            fold_importance = pd.DataFrame()
            fold_importance["feature"] = columns
            fold_importance["importance"] = model.feature_importances_
            fold_importance["fold"] = fold_n + 1
            feature_importance = pd.concat([feature_importance, fold_importance], axis=0)

        if model_type == 'xgb' and plot_feature_importance:
            # feature importance
            fold_importance = pd.DataFrame()
            fold_importance["feature"] = columns
            fold_importance["importance"] = model.feature_importances_
            fold_importance["fold"] = fold_n + 1
            feature_importance = pd.concat([feature_importance, fold_importance], axis=0)
    prediction /= n_splits
    print('CV mean score: {0:.4f}, std: {1:.4f}.'.format(np.mean(scores), np.std(scores)))

    result_dict['oof'] = oof
    result_dict['prediction'] = prediction
    result_dict['acc_scores'] = acc_scores
    result_dict['scores'] = scores


    if model_type == 'lgb' or model_type == 'xgb':
        if plot_feature_importance:
            feature_importance["importance"] /= n_splits
            cols = feature_importance[["feature", "importance"]].groupby("feature").mean().sort_values(
                by="importance", ascending=False)[:50].index

            best_features = feature_importance.loc[feature_importance.feature.isin(cols)]

            plt.figure(figsize=(16, 12))
            sns.barplot(x="importance", y="feature", data=best_features.sort_values(by="importance", ascending=False))
            plt.title('LGB Features (avg over folds)')
            plt.show()
            result_dict['feature_importance'] = feature_importance
    end_time = time.time()

    print("train_model_classification cost time:{}".format(end_time - start_time))
    return result_dict

进行训练和预测

采用10折交叉验证，效果要好于5折和20折。

cat_params = {'learning_rate': 0.1, 'depth': 9, 'l2_leaf_reg': 10, 'bootstrap_type': 'Bernoulli',#'task_type': 'GPU',
              'od_type': 'Iter', 'od_wait': 50, 'random_seed': 11, 'allow_writing_files': False}

n_fold = 10
num_classes = 2
print("分类个数num_classes:{}".format(num_classes))
folds = StratifiedKFold(n_splits=n_fold, random_state=1314, shuffle=True)


result_dict_cat = train_model_classification(X=X,
                                             X_test=test[feature],
                                             y=Y,
                                             params=cat_params,
                                             num_classes=num_classes,
                                             folds=folds,
                                             model_type='cat',
                                             eval_metric='logloss',
                                             plot_feature_importance=True,
                                             verbose=1,
                                             early_stopping_rounds=800,#原400
                                             n_folds=n_fold)

最终结果

[0.9032051282051282, 0.9058333333333334, 0.9024358974358975, 0.9044871794871795, 0.9055769230769231, 0.9019230769230769, 0.9071153846153847, 0.9091025641025641, 0.9046153846153846, 0.9057051282051282]
[0.940374324805705, 0.9433745066510744, 0.9367520694627971, 0.9416194244693141, 0.9405878127004588, 0.9378354914113705, 0.9418489996834368, 0.9442885857569249, 0.9411564723924757, 0.9421991199077591]
CV mean score: 0.9410, std: 0.0022.
train_model_classification cost time:1650.3819825649261