# multilabel classfication

from sklearn.multiclass import OneVsRestClassifier

# Linear Models

from sklearn.linear_model import LogisticRegression

from sklearn.discriminant_analysis import LinearDiscriminantAnalysis

from sklearn.svm import LinearSVC

from sklearn.naive_bayes import MultinomialNB

from lightgbm import LGBMClassifier

def train_classifier(X_train, y_train, X_valid=None, y_valid=None, C=1.0, model='lr'):

    """

      X_train, y_train — training data

      return: trained classifier

    """

    if model=='lr':

        model = LogisticRegression(C=C, penalty='l1', solver='liblinear')

        model = OneVsRestClassifier(model)

        model.fit(X_train, y_train)

    elif model=='svm':

        model = LinearSVC(C=C, penalty='l1', loss='squared_hinge')

        model = OneVsRestClassifier(model)

        model.fit(X_train, y_train)

    elif model=='nbayes':

        model = MultinomialNB(alpha=1.0)

        model = OneVsRestClassifier(model)

        model.fit(X_train, y_train)

    elif model=='lda':

        model = LinearDiscriminantAnalysis(solver='svd')

        model = OneVsRestClassifier(model)

        model.fit(X_train, y_train)

    return model