add yield_task.py to class task(yield)

Author: junhuanchen

13.system/yield_task.py

@@ -0,0 +1,63 @@
+
+class Task:
+
+    def __init__(self, event=(lambda : print('task running'))):
+        self.event = event
+        self.cb = self.pre()
+        next(self.cb)
+        print('task init')
+
+    def pre(self):
+        print('task start')
+        flag = True
+        while flag is True:
+            flag = yield flag
+            self.event()
+        print('task exit')
+
+    def run(self, flag = True):
+        try:
+            res = self.cb.send(flag)
+            return res
+        except StopIteration as e:
+            return False
+
+if __name__ == "__main__":
+    tmp = Task()
+
+    assert(tmp.run())
+    assert(tmp.run())
+    assert(False == tmp.run(False))
+
+    print(tmp.run())
+    print(tmp.run(False))
+
+
+    class music:
+
+        def __init__(self):
+            self.task = Task(self.pre)
+            self.args = None
+            print('music init')
+
+        def pre(self):
+            print('pre ', self.args)
+
+        def play(self, size=10):
+            self.args = list(range(size))
+            print(self.task.run())
+
+        def stop(self):
+            print(self.task.run(False))
+            self.__init__()
+
+        def loop(self):
+            self.alive = False
+            while self.alive:
+                self.play()
+            stop()
+
+    tmp = music()
+    tmp.play()
+    tmp.stop()
+    tmp.play()