浅谈python中append和extend区别

append和extend均可以做2个列表/tuple的连接,但是连接结果并不相同，查看方法注释，append是在列表追加object对象，extend是追加元素。

a = [1, 2, 3]
b = [3, 4]
# a.append(b)
a.extend(b)

print(a)

使用append输出结果为[1, 2, 3, [4, 5]]

使用extend输出结果为 [1, 2, 3, 4, 5]

    def append(self, *args, **kwargs): # real signature unknown
        """ Append object to the end of the list. """
        pass

    def extend(self, *args, **kwargs): # real signature unknown
        """ Extend list by appending elements from the iterable. """
        pass