內部類+抽象方法+鏈式調用實現python的建造者模式

 

 

使用 內部類 與抽象繼承的方式實現建造者模式,鏈式調用的方式代碼簡潔;

子類繼承實現實際的建造方法方便擴展.

代碼如下:

 

# -*- coding:utf-8 -*-

import abc
import random


class Product(object):
    def __init__(self, product_id=random.random()):
        self.uuid = product_id
        self.factor = None
        self.date = None

    def set_factor(self, factor):
        self.factor = factor

    def set_date(self, date):
        self.date = date

    # 內部類,作爲建造者類的父類
    class Abs_Buildder(object):
        def __init__(self):
            self.factor = "Default_Factor"
            self.date = "Today!"

        # 子類實現該方法時必須返回self,用來實現鏈式調用
        @abc.abstractmethod
        def set_factor(self, factor):
            pass

        # 子類實現該方法時必須返回self,用來實現鏈式調用
        @abc.abstractmethod
        def set_date(self, date):
            pass

        def build_product(self):
            product = Product()
            product.set_factor(self.factor)
            product.set_date(self.date)
            return product


# 實際建造者類
class OneBuilder(Product.Abs_Buildder):
    def __init__(self):
        super(OneBuilder, self).__init__()

    def set_factor(self, factor):
        print("one factor")
        self.factor = factor
        return self

    def set_date(self, date):
        print("One_date")
        self.date = date
        return self


# 實際建造者類
class TwoBuilder(Product.Abs_Buildder):
    def __init__(self):
        super(TwoBuilder, self).__init__()

    def set_factor(self, factor):
        print("Two_Factor")
        self.factor = factor
        return self

    def set_date(self, date):
        print("Two_date")
        self.date = date
        return self


if __name__ == "__main__":
    one_b = OneBuilder()
    two_b = TwoBuilder()
    product1 = OneBuilder().set_factor("1").set_date("yoyo1").build_product()
    print(product1)
    product2 = TwoBuilder().set_factor("2").set_date("gaga2").build_product()
    print(product2)

    exit(0)

運行一下:

C:\Python27\python.exe D:/代碼/python-DP/builder-test.py
one factor
One_date
<__main__.Product object at 0x033651B0>
Two_Factor
Two_date
<__main__.Product object at 0x03365290>

Process finished with exit code 0