-*- coding: utf-8 -*-

class Person(type):

def __new__(cls, *args, **kwargs):
    print('__new__ called.')
    return type.__new__(cls, *args, **kwargs)

def __init__(self, *args, **kwargs):
    print('__init__ called.')
    super(Person, self).__init__(*args, **kwargs)
    self.name = kwargs.get('name', 'wls')
    self.age = kwargs.get('age', '30')

def __str__(self):
    return '<Person: %s(%s)>' % (self.name, self.age)

if name == '__main__':
piglei = Person(name='Wnagchengzhan', age=29)
print(piglei)

你那些代码在python 2.x 里运行应该是没问题的，但是在python 3.x 里已经无法运行了，type.__new__ 已经没办法运行了，具体原因我也没查到
可以考虑把type改成object，另外 name直接使用会报错，没有声明，内置的是 name
我修改后的代码如下：

 # -*- coding: utf-8 -*-
class Person(object):
    def __new__(cls, *args, **kwargs):
        print('__new__ called.')
        return super(Person, cls).__new__(cls)

    def __init__(self, *args, **kwargs):
        print('__init__ called.')
        super(Person, self).__init__()
        self.name = kwargs.get('name', 'wls')
        self.age = kwargs.get('age', '30')

    def __str__(self):
        return '<Person: %s(%s)>' % (self.name, self.age)
if __name__ == '__main__':
    piglei = Person(name='Wnagchengzhan', age=29)
    print(piglei)

if name == '__main__':
piglei = Person(name='Wnagchengzhan', age=29)
print(piglei)

函数入口应该改为：
if name=="__main__":
piglei=Person(name='Wnagchengzhan', age=29)
print(piglei)