Question

我想让构造函数重载，在这里我可以同时为两个参数和实际数量传递无。

class ABC(object):

    def __init__(self, query = None, cands = None):
        if query != None and cands != None:
           self.query = query
           self.cands = cands
           self.getIDF()


    def getIDF(self):
        self.i_dict = {}
        for term in query:
            count = 0
            for cand in cands:
                if term in cand:
                    count += 1
            self.i_dict[term] = count

然后我创建实例：abc = ABC(query, cands) 由于查询和Cands不是None，因此应该触发self.getIDF()，但仍然出现错误：

NameError: name 'query' is not defined

似乎查询未传递到函数中，为什么？

Answer 1

您可以在课堂上进行一些更改和修正

您想使用self在query中调用类属性cands和getIDF，因此它将变为self.query和self.cands。 / p>
您只能执行if query and cands:而不是if query != None and cands != None:。
考虑在构造函数本身中定义self.i_dict = {}

具有这些建议的更新的类可能看起来像

class ABC(object):

    def __init__(self, query = None, cands = None):

        #i_dict defined in constructor
        self.i_dict = {}

        #Changed the if condition
        if query and cands:
           self.query = query
           self.cands = cands
           self.getIDF()

    def getIDF(self):

        #Use self to call class attribute
        for term in self.query:
            count = 0
            # Use self to call class attribute
            for cand in self.cands:
                if term in cand:
                    count += 1
            self.i_dict[term] = count

Python构造函数重载无法正常工作吗？

1 个答案: