# 建造者

```python
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2019/10/7 8:02 PM
# @Author  : xinfa.jiang
# @Site    : 
# @File    : builder.py
# @Software: PyCharm
'''
建造者模式
将一个复杂对象的构建与它的表示分离, 使得同样的构建过程可以创建不同的表示
'''
from abc import ABCMeta, abstractmethod


class Product(object):
    """
    具体产品
    """

    def __init__(self):
        self.__parts = []

    def add(self, part):
        self.__parts.append(part)

    def show(self):
        print('-'.join(self.__parts))


class Builder(object):
    """
    为创建一个product对象的各个部件指定的抽象接口
    """

    __metaclass__ = ABCMeta

    @abstractmethod
    def build_part_1(self):
        pass

    @abstractmethod
    def build_part_2(self):
        pass

    @abstractmethod
    def get_result(self):
        pass


class BuilderA(Builder):
    """
    具体建造者A
    """

    def __init__(self):
        self.__product = Product()

    def build_part_1(self):
        self.__product.add("partA1")

    def build_part_2(self):
        self.__product.add("partA2")

    def get_result(self):
        return self.__product


class BuilderB(Builder):
    """
    具体建造者B
    """

    def __init__(self):
        self.__product = Product()

    def build_part_1(self):
        self.__product.add("partB1")

    def build_part_2(self):
        self.__product.add("partB2")

    def get_result(self):
        return self.__product


class Director(object):
    """
    指挥构建过程
    director不知道自己用的是哪个, 即: 只有不知道, 才能随时替换
    """

    @staticmethod
    def construct(builder):
        builder.build_part_1()
        builder.build_part_2()


if __name__ == '__main__':
    ba = BuilderA()
    bb = BuilderB()

    Director.construct(ba)
    product = ba.get_result()
    product.show()

    Director.construct(bb)
    product = bb.get_result()
    product.show()
```


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