更好的方法是使用isinstance和type转换。如果我没理解错的话，你想要的是

def __init__ (self, filename):
    if isinstance (filename, basestring):
        # filename is a string
    else:
        # try to convert to a list
        self.path = list (filename)

你为什么不更像蟒蛇?

class AutoList:
def __init__(self, inp):
    try:                        ## Assume an opened-file...
        self.data = inp.read()
    except AttributeError:
        try:                    ## Assume an existent filename...
            with open(inp, 'r') as fd:
                self.data = fd.read()
        except:
            self.data = inp     ## Who cares what that might be?

非常好的问题。我也解决了这个问题，虽然我同意“工厂”(类方法构造函数)是一个很好的方法，但我想建议另一个我也发现非常有用的方法:

下面是一个示例(这是一个read方法而不是构造函数，但思想是相同的):

def read(self, str=None, filename=None, addr=0):
    """ Read binary data and return a store object. The data
        store is also saved in the interal 'data' attribute.

        The data can either be taken from a string (str 
        argument) or a file (provide a filename, which will 
        be read in binary mode). If both are provided, the str 
        will be used. If neither is provided, an ArgumentError 
        is raised.
    """
    if str is None:
        if filename is None:
            raise ArgumentError('Please supply a string or a filename')

        file = open(filename, 'rb')
        str = file.read()
        file.close()
    ...
    ... # rest of code

这里的关键思想是使用Python对命名参数的出色支持来实现这一点。现在，如果我想从文件中读取数据，我说:

obj.read(filename="blob.txt")

为了从字符串中读取它，我说:

obj.read(str="\x34\x55")

这样用户就只有一个方法可以调用。如您所见，在内部处理它并不过于复杂

你可能需要isinstance内置函数:

self.data = data if isinstance(data, list) else self.parse(data)

更好的方法是使用isinstance和type转换。如果我没理解错的话，你想要的是

def __init__ (self, filename):
    if isinstance (filename, basestring):
        # filename is a string
    else:
        # try to convert to a list
        self.path = list (filename)

你应该使用isinstance

isinstance(...)
    isinstance(object, class-or-type-or-tuple) -> bool

    Return whether an object is an instance of a class or of a subclass thereof.
    With a type as second argument, return whether that is the object's type.
    The form using a tuple, isinstance(x, (A, B, ...)), is a shortcut for
    isinstance(x, A) or isinstance(x, B) or ... (etc.).