Shulou(Shulou.com)05/31 Report--

In this article, the editor introduces in detail "how to create the blinker signal library of python". The content is detailed, the steps are clear, and the details are handled properly. I hope that this article "how to create the blinker signal library of python" can help you solve your doubts.

I. installation

A powerful Python-based semaphore that supports both simple object-to-object communication and multicast for multiple objects

Support for registering global named signals and custom named signals

Support for anonymous signals, thread safety

Support persistent and transient connections to the recipient

Automatic disconnection from the recipient through weak references

Support for sending data of any size and collecting the return value of the receiver of the signal

Pip install blinker II. Create and send signals

The signal is created by the signal () method

The signal is sent by the send () method

From blinker import signal# creates a signal and names it s = signal ('autofelix') def say (args): print (' I am Flying Rabbit') # signal registers a receiver s.connect (say) if "_ _ main__" = = _ _ name__:# send signal s.send () 3. Anonymous signal

Blinker also supports anonymous signals, but there is no need to specify a specific signal value.

Each anonymous signal created is independent of each other.

From blinker import signal# creates an anonymous signal s = signal () def say (args): print ('I am Flying Rabbit') # signal registers a receiver s.connect (say) if "_ _ main__" = = _ _ name__:# send signal s.send () 4. Multicast signal

Multicast signal is a characteristic that can reflect the advantages of signal.

Multiple receivers register with the signal, and the sender only needs to send the message once to transmit the information to multiple receivers.

From blinker import signals = signal ('autofelix') def fans_one (args): print (f' I am a fan number one, I follow: {args}') def fans_two (args): print (f'I am a fan number two, I follow: {args}') s.connect (fans_one) s.connect (fans_two) if "_ _ main__" = _ _ name__:s.send ('flying rabbit') V, recipient subscription topic

It is sent to the recipient only when the specified subject sends a message

From blinker import signals = signal ('autofelix') def fans (args): print (f' I am a little fan, {args} is my teacher') # signal registers a receiver and specifies the theme s.connect (animal, sender=' Flying Rabbit') if "_ main__" = _ _ name__:for I in ['Flying Rabbit', 'Flying Rabbit Little Sister', 'Flying Rabbit Little Brother']: s.send (I) VI, Decoration usage

In addition to function registration, there is a simpler method of signal registration, which is the decorator.

From blinker import signals = signal ('autofelix') @ s.connectdef fans_one (args): print (I am a fan number one, I follow: {args}') @ s.connectdef fans_two (args): print (f'I am a fan number two, I follow: {args}') if "_ main__" = = _ name__:s.send ('flying rabbit') 7. Subscribe theme decorator

One drawback of connect's registration method using decorators is that they cannot subscribe to topics.

The connect_via method supports subscribing to topics

From blinker import signals = signal ('autofelix') @ s.connect_via (' Flying Rabbit') def fans (args): print (f'I am a little fan, {args} is my teacher') if "_ _ main__" = = _ name__:for I in ['Flying Rabbit', 'Flying Rabbit Little Sister', 'Flying Rabbit Little Brother']: s.send (I) VIII. Check whether there is a receiver.

If it takes a long time for a sender to prepare before sending a message

In order to avoid wasting performance caused by no receiver

You can first check whether a signal has a receiver.

Send only when it is certain that there is a recipient

From blinker import signala1 = signal ('autofelix-1') a2 = signal (' autofelix-2') def fans (sender): print ('I'm a little fan') a1.connect (fans) if "_ _ main__" = = _ _ name__:res = a1.receiversprint (res) if res:a1.send () res = a2.receiversprint (res) if res:a2.send () else:print ("I'm an idol") IX, whether you subscribe to a signal

Check whether the subscriber is caused by a certain signal

From blinker import signala1 = signal ('autofelix-1') a2 = signal (' autofelix-2') def fans (sender): print ('I'm a little fan') a1.connect (fans) if "_ _ main__" = _ _ name__:res = a1.has_receivers_for (fans) print (res) res = a2.has_receivers_for (fans) print (res). This article "how to create python's blinker signal Library" has been introduced. If you want to master the knowledge of this article, you still need to practice and use it. If you want to know more about the articles, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.