我可以将其表示为生成器/协同程序吗？

Question

Suppose I have the following class:

class MyGen(object):
  def next(self):
    return X()

  def send(self, x):
    return f(x)

Is it possible to express it as a single function, using the yield keyword? Suppose I have g = MyGen() . Note that g.next() shouldn't call f() , and g.send(x) shouldn't call X() , but f() and X() could share some code.

Answer 1

This code will be almost equivalent:

def my_gen(x=None):
    while True:
        if x is None:
            x = yield X()
        else:
            x = yield f(x)

One difference is that you can't send a value (other than None ) to a generator before calling next() for the first time. Another difference is that sending None won't trigger calling f() , since the generator can't distinguish send(None) and next() .

Answer 2

Sven的配方正是要走的路，我只是想补充一点，如果你想了解更多有关Python中的生成器，协程等的信息，那么这个网站就是你要去的地方。