Python:如何正确调用方法

Question

我有这个类：

class Tumor(object):
    """
    Wrapper for the tumor data points.
    Attributes:
        idNum = ID number for the tumor (is unique) (int)
        malignant = label for this tumor (either 'M' for malignant 
                    or 'B' for benign) (string)
        featureNames = names of all features used in this Tumor 
                       instance (list of strings)
        featureVals = values of all features used in this Tumor
                       instance, same order as featureNames (list of floats)
    """
    def __init__(self, idNum, malignant, featureNames, featureVals):
        self.idNum = idNum
        self.label = malignant
        self.featureNames = featureNames
        self.featureVals = featureVals
    def distance(self, other):
        dist = 0.0
        for i in range(len(self.featureVals)):
            dist += abs(self.featureVals[i] - other.featureVals[i])**2
        return dist**0.5
    def getLabel(self):
        return self.label
    def getFeatures(self):
        return self.featureVals
    def getFeatureNames(self):
        return self.featureNames
    def __str__(self):
        return str(self.idNum) + ', ' + str(self.label) + ', ' 
               + str(self.featureVals)

我正试图在稍后的代码中的另一个函数中使用它的实例：

def train_model(train_set):
    """
    Trains a logistic regression model with the given dataset
    train_set (list): list of data points of type Tumor
    Returns a model of type sklearn.linear_model.LogisticRegression
            fit to the training data
    """
    tumor = Tumor()
    features = tumor.getFeatures()
    labels = tumor.getLabel()
    log_reg = sklearn.linear_model.LogisticRegression(train_set)
    model = log_reg.fit(features, labels)
    return model

然而，当我测试我的代码时，我一直收到这个错误：

TypeError: __init__() takes exactly 5 arguments (1 given)

我知道当我在train_model中创建Tumor的实例时，我没有使用这五个参数，但我该怎么做呢？

Answer 1

__init__（或__new__，如果您正在使用它）的参数可以预见地转到您在train_model:中创建实例的位置

tumor = Tumor(idNum, malignant, featureNames, featureVals)

当然，您实际上需要所有这些的值，因为它们都是必需的参数。

但是，您不需要包含self，因为第一个参数是自动处理的。