from sklearn.neighbors import KNeighborsClassifier
from sklearn import tree
from sklearn.naive_bayes import GaussianNB
from sklearn.svm import SVC
from sklearn.ensemble import RandomForestClassifier


def which_classifier(classifier='5NN'):
    if (classifier == '5NN'):
        return KNeighborsClassifier(5)
    elif (classifier == 'C4.5'):
        return tree.DecisionTreeClassifier()
    elif (classifier == 'NB'):
        return GaussianNB()
    elif (classifier == 'SVM'):
        return SVC(probability=True, gamma='auto')
    elif (classifier == 'RF'):
        return RandomForestClassifier()