是否有避免在初始化类时调用它的方法,例如从类方法中调用__init__
?
[我试图在Python中创建一个不区分大小写和标点符号的字符串类,以进行有效的比较,但是在不调用__init__
的情况下创建新实例时遇到了麻烦。
>>> class String: def __init__(self, string): self.__string = tuple(string.split()) self.__simple = tuple(self.__simple()) def __simple(self): letter = lambda s: ''.join(filter(lambda s: 'a' <= s <= 'z', s)) return filter(bool, map(letter, map(str.lower, self.__string))) def __eq__(self, other): assert isinstance(other, String) return self.__simple == other.__simple def __getitem__(self, key): assert isinstance(key, slice) string = String() string.__string = self.__string[key] string.__simple = self.__simple[key] return string def __iter__(self): return iter(self.__string) >>> String('Hello, world!')[1:] Traceback (most recent call last): File "<pyshell#2>", line 1, in <module> String('Hello, world!')[1:] File "<pyshell#1>", line 17, in __getitem__ string = String() TypeError: __init__() takes exactly 2 positional arguments (1 given) >>>
我应该用什么替换
string = String(); string.__string = self.__string[key]; string.__simple = self.__simple[key]
来用切片初始化新对象?
编辑:
受下面编写的答案的启发,已对初始化程序进行了编辑,以快速检查是否没有参数。
def __init__(self, string=None):
if string is None:
self.__string = self.__simple = ()
else:
self.__string = tuple(string.split())
self.__simple = tuple(self.__simple())
是否有避免在初始化类时调用__init__的方法,例如从类方法中调用它?我试图在Python中创建一个不区分大小写和标点符号的字符串类,用于...