DEAP源码解析

框架

DEAP架构特点为

• 组件-流程分离
• 模块化组件
• 函数式编程：函数组合替代继承

类创建

通过create来创建，通过元类来创建类

def create(name, base, **kargs):
	if name in globals():
        warnings.warn("A class named '{0}' has already been created and it "
                      "will be overwritten. Consider deleting previous "
                      "creation of that class or rename it.".format(name),
                      RuntimeWarning)

    # Check if the base class has to be replaced
    if base in class_replacers:
        base = class_replacers[base]
    meta_create(name, base, kargs)

def meta_create(name, base, dct):
    class_ = MetaCreator(name, base, dct)
    globals()[name] = class_
    return class_

class MetaCreator(type):
    def __new__(cls, name, base, dct):
        return super(MetaCreator, cls).__new__(cls, name, (base,), dct)

    def __init__(cls, name, base, dct):
        # A DeprecationWarning is raised when the object inherits from the
        # class "object" which leave the option of passing arguments, but
        # raise a warning stating that it will eventually stop permitting
        # this option. Usually this happens when the base class does not
        # override the __init__ method from object.
        dict_inst = {}
        dict_cls = {}
        for obj_name, obj in dct.items():
            if isinstance(obj, type):
                dict_inst[obj_name] = obj
            else:
                dict_cls[obj_name] = obj

        def init_type(self, *args, **kargs):
            """Replace the __init__ function of the new type, in order to
            add attributes that were defined with **kargs to the instance.
            """
            for obj_name, obj in dict_inst.items():
                setattr(self, obj_name, obj())
            if base.__init__ is not object.__init__:
                base.__init__(self, *args, **kargs)

        cls.__init__ = init_type
        cls.reduce_args = (name, base, dct)
        super(MetaCreator, cls).__init__(name, (base,), dict_cls)

    def __reduce__(cls):
        return (meta_create, cls.reduce_args)