我知道pydispatcher,但是Python周围一定有其他与事件相关的包。
哪些库是可用的?
我对作为大型框架一部分的事件管理器不感兴趣,我宁愿使用可以轻松扩展的小型骨架解决方案。
我知道pydispatcher,但是Python周围一定有其他与事件相关的包。
哪些库是可用的?
我对作为大型框架一部分的事件管理器不感兴趣,我宁愿使用可以轻松扩展的小型骨架解决方案。
当前回答
你可以看看pymitter (pypi)。它是一个小的单文件(~250 loc)方法 提供名称空间、通配符和TTL。
这里有一个基本的例子:
from pymitter import EventEmitter
ee = EventEmitter()
# decorator usage
@ee.on("myevent")
def handler1(arg):
print "handler1 called with", arg
# callback usage
def handler2(arg):
print "handler2 called with", arg
ee.on("myotherevent", handler2)
# emit
ee.emit("myevent", "foo")
# -> "handler1 called with foo"
ee.emit("myotherevent", "bar")
# -> "handler2 called with bar"
其他回答
下面是另一个需要考虑的模块。对于要求更高的应用程序,这似乎是一个可行的选择。
Py-notify is a Python package providing tools for implementing Observer programming pattern. These tools include signals, conditions and variables. Signals are lists of handlers that are called when signal is emitted. Conditions are basically boolean variables coupled with a signal that is emitted when condition state changes. They can be combined using standard logical operators (not, and, etc.) into compound conditions. Variables, unlike conditions, can hold any Python object, not just booleans, but they cannot be combined.
如果我在pyQt中做代码,我使用QT套接字/信号范式,django也是如此
如果我正在做异步I/O,我使用本机选择模块
如果我使用SAX python解析器,我使用SAX提供的事件API。所以看起来我是底层API的受害者:-)
也许你应该问问自己,你对事件框架/模块有什么期望。我个人倾向于使用qt中的Socket/Signal范例。更多关于这方面的信息可以在这里找到
你可以看看pymitter (pypi)。它是一个小的单文件(~250 loc)方法 提供名称空间、通配符和TTL。
这里有一个基本的例子:
from pymitter import EventEmitter
ee = EventEmitter()
# decorator usage
@ee.on("myevent")
def handler1(arg):
print "handler1 called with", arg
# callback usage
def handler2(arg):
print "handler2 called with", arg
ee.on("myotherevent", handler2)
# emit
ee.emit("myevent", "foo")
# -> "handler1 called with foo"
ee.emit("myotherevent", "bar")
# -> "handler2 called with bar"
这里是一个最小的设计,应该工作得很好。你要做的就是简单地在一个类中继承Observer,然后使用observe(event_name, callback_fn)来监听特定的事件。当特定事件在代码中的任何地方被触发时(例如。事件('USB connected')),则将触发相应的回调。
class Observer():
_observers = []
def __init__(self):
self._observers.append(self)
self._observed_events = []
def observe(self, event_name, callback_fn):
self._observed_events.append({'event_name' : event_name, 'callback_fn' : callback_fn})
class Event():
def __init__(self, event_name, *callback_args):
for observer in Observer._observers:
for observable in observer._observed_events:
if observable['event_name'] == event_name:
observable['callback_fn'](*callback_args)
例子:
class Room(Observer):
def __init__(self):
print("Room is ready.")
Observer.__init__(self) # DON'T FORGET THIS
def someone_arrived(self, who):
print(who + " has arrived!")
# Observe for specific event
room = Room()
room.observe('someone arrived', room.someone_arrived)
# Fire some events
Event('someone left', 'John')
Event('someone arrived', 'Lenard') # will output "Lenard has arrived!"
Event('someone Farted', 'Lenard')
我创建了一个EventManager类(代码在最后)。语法如下:
#Create an event with no listeners assigned to it
EventManager.addEvent( eventName = [] )
#Create an event with listeners assigned to it
EventManager.addEvent( eventName = [fun1, fun2,...] )
#Create any number event with listeners assigned to them
EventManager.addEvent( eventName1 = [e1fun1, e1fun2,...], eventName2 = [e2fun1, e2fun2,...], ... )
#Add or remove listener to an existing event
EventManager.eventName += extra_fun
EventManager.eventName -= removed_fun
#Delete an event
del EventManager.eventName
#Fire the event
EventManager.eventName()
下面是一个例子:
def hello(name):
print "Hello {}".format(name)
def greetings(name):
print "Greetings {}".format(name)
EventManager.addEvent( salute = [greetings] )
EventManager.salute += hello
print "\nInitial salute"
EventManager.salute('Oscar')
print "\nNow remove greetings"
EventManager.salute -= greetings
EventManager.salute('Oscar')
输出:
最初的敬礼 问候奥斯卡 你好奥斯卡 现在删除问候语 你好奥斯卡
事件经理代码:
class EventManager:
class Event:
def __init__(self,functions):
if type(functions) is not list:
raise ValueError("functions parameter has to be a list")
self.functions = functions
def __iadd__(self,func):
self.functions.append(func)
return self
def __isub__(self,func):
self.functions.remove(func)
return self
def __call__(self,*args,**kvargs):
for func in self.functions : func(*args,**kvargs)
@classmethod
def addEvent(cls,**kvargs):
"""
addEvent( event1 = [f1,f2,...], event2 = [g1,g2,...], ... )
creates events using **kvargs to create any number of events. Each event recieves a list of functions,
where every function in the list recieves the same parameters.
Example:
def hello(): print "Hello ",
def world(): print "World"
EventManager.addEvent( salute = [hello] )
EventManager.salute += world
EventManager.salute()
Output:
Hello World
"""
for key in kvargs.keys():
if type(kvargs[key]) is not list:
raise ValueError("value has to be a list")
else:
kvargs[key] = cls.Event(kvargs[key])
cls.__dict__.update(kvargs)