构造函数声明的语法：

def __init __（self）：
    ＃构造函数的主体

参数化构造函数的示例：

class Addition:

first = 0

second = 0

answer = 0

# parameterized constructor

def __init__(self, f, s):

self.first = f

self.second = s

def display(self):

print("First number = " + str(self.first))

print("Second number = " + str(self.second))

print("Addition of two numbers = " + str(self.answer))

def calculate(self):

self.answer = self.first + self.second

# creating object of the class

# this will invoke parameterized constructor

obj = Addition(1000, 2000)

# perform Addition

obj.calculate()

# display result

obj.display()

输出：

First number =1000
Second number =2000
Addition of two numbers =3000