class taskflow.atom.Atom(name=None, provides=None, requires=None, auto_extract=True, rebind=None, inject=None, ignore_list=None, revert_rebind=None, revert_requires=None)[source]
    """
    基类: object

    An unit of work that causes a flow to progress (in some manner).
    一个让flow以某种方式进行的工作单位

    An atom is a named object that operates with input data to perform some action that furthers the overall flows progress. It usually also produces some of its own named output as a result of this process.

    atom是被命名过,通过输入的数据来控制的对象
    atom用于执行一些动作来确保整体flow正确运行
    它通常产生一些由自身命名的过程结果输出

    Parameters:

    name – Meaningful name for this atom, should be something that is distinguishable and understandable for notification, debugging, storing and any other similar purposes.
    一个有意义的名字,必须在通知、调试、存储等行为中可辨识和可以理解的

    provides – A set, string or list of items that this will be providing (or could provide) to others, used to correlate and associate the thing/s this atom produces, if it produces anything at all.
    可以是set、string或者items组成的列表, 这些对象将提供或者可以提供给其他（对象）
    用于将当前atome和这些对象关联,如果这些对象能产生任何东西的话

    inject – An immutable input_name => value dictionary which specifies any initial inputs that should be automatically injected into the atoms scope before the atom execution commences (this allows for providing atom local values that do not need to be provided by other atoms/dependents).
    一个不可变的name->value字典, 他指定了必须在atome执行之前自动注入到当前atom区域的初始化输入值
    通过这种方式允许提供给atom一个不需要提供给其他atom/dependents的local本地值

    rebind – A dict of key/value pairs used to define argument name conversions for inputs to this atom’s execute method.
    一个k/v字典, 用于提供参数转换atome的execute method参数名

    revert_rebind – The same as rebind but for the revert method. If unpassed, rebind will be used instead.
    一个k/v字典,提供参数给revert method用,revert method未能通过,rebind的的值将用于revert method
    1.3版本里没有这个参数

    requires – A set or list of required inputs for this atom’s execute method.
    一个set/list, 用于指定execute method运行必要的输入

    revert_requires – A set or list of required inputs for this atom’s revert method. If unpassed, `requires will be used.
    同上,用于revert method, 为你能通过使用requires的值
    1.3版本里没有这个参数


    Variables:
    version – An immutable version that associates version information with this atom. It can be useful in resuming older versions of atoms. Standard major, minor versioning concepts should apply.
    atom的版本号,不可变,在恢复旧版atomes的时候会非常有用.主版本和次要版本的概念是适用的
    也就是允许 a.b 的版本号形式,a表主要版本,b表次要版本


    save_as – An immutable output resource name OrderedDict this atom produces that other atoms may depend on this atom providing. The format is output index (or key when a dictionary is returned from the execute method) to stored argument name.
    一个不可变的输出资源名字典, 这个atom提供的资源是其他的atome可能依赖的
    格式是输出索引（如果execute method返回的是字典,那么输出的就是字典的key）到存储参数名
    1.3版代码中save_as是一个有序字典（OrderedDict）


    priority = 0
    A numeric priority that instances of this class will have when running,
    used when there are multiple parallel candidates to execute and/or revert.
    During this situation the candidate list will be stably sorted based on
    this priority attribute which will result in atoms with higher priorities
    executing (or reverting) before atoms with lower priorities (higher being
    defined as a number bigger, or greater than an atom with a lower priority number).
    By default all atoms have the same priority (zero).
    For example when the following is combined into a graph (where each node in the denoted graph is some task):
        a -> b
        b -> c
        b -> e
        b -> f
    When b finishes there will then be three candidates that can run (c, e, f)
    and they may run in any order. What this priority does is sort those three
    by their priority before submitting them to be worked on (so that instead
    of say a random run order they will now be ran by there sorted order).
    This is also true when reverting (in that the sort order of the potential
    nodes will be used to determine the submission order).
    这就不详细翻译了,简单说明下
    a执行完后执行b, b执行完后可以执行c e f,执行顺序是不确定的,
    设置了priority, c e f的执行顺序就有优先级了
    还原的时候优先级也有效


    requires – A OrderedSet of inputs this atom requires to function.
    通过上面参数requires生成的有序字典 key就是参数名字, value是参数别名
    默认情况下key==value, key!=value的情况看下面rebind

    rebind – An immutable input resource OrderedDict that can be used to
    alter the inputs given to this atom. It is typically used for mapping
    a prior atoms output into the names that this atom expects
    (in a way this is like remapping a namespace of another atom into the namespace of this atom).
    这里不翻译了,看下面的代码说明

    revert_rebind – The same as rebind but for the revert method. This should only differ from rebind if the revert method has a different signature from execute or a different revert_rebind value was received.
    inject – See parameter inject.
    Atom.name – See parameter name.
    requires – A OrderedSet of inputs this atom requires to function.
    optional – A OrderedSet of inputs that are optional for this atom to execute.
    revert_optional – The revert version of optional.
    provides – A OrderedSet of outputs this atom produces.
    相当于返回值的作为关联task的参数名,和上面rebind相关
    """