面向对象之构造方法

__init__　　# 只要类名后面加()， 就会自动执行该类的__init__方法

如下：

class SQLHelper:
    h_host = ‘cl.salt.com2‘
    u_username = ‘alex2‘
    u_password = ‘1234‘

    def __init__(self):
        print(‘自动执行__init__方法‘)

    def fetch(self, sql):
        print(self.h_host)
        print(self.u_username)
        print(self.u_password)
        print(sql)

    def create(self, sql):
        pass

    def remove(self, nid):
        pass

    def modify(self, name):
        pass

obj = SQLHelper()