简单了解python协程的相关知识

'''
1,协程的实现原理,底层通过 yield 实现
'''
def work1(): #工作任务
  for i in range(10):
    print('work1----{}'.format(i))
    yield i
def work2():
  for i in range(10):
    print('work2----{}'.format(i))
    yield i
def work3():
  for i in range(10):
    print('work3----{}'.format(i))
    yield i
g1 = work1()
g2 = work2()
g3 = work3()
while True: #循环调用生成器实现任务切换
  try:
    print(next(g1))
    print(next(g2))
    print(next(g3))
  except StopIteration :
    pass
    break

python -m pip install greenlet

'''
1,展示greenelent ,不能自动切换需要手动切换
'''
import greenlet
def work1():
  for i in range(10):
     print('work1----{}'.format(i))
     g2.switch()  #切换到g2
def work2():
  for i in range(10):
     print('work2----{}'.format(i))
     g1.switch() #切换到g1
g1 = greenlet.greenlet(work1) #返回协程对象
g2 = greenlet.greenlet(work2)
g1.switch() #启动开关

'''
协程gevent IO操作会切换
'''
import gevent
def work1(): # 工作任务
  for i in range(10):
    print('work1----{}'.format(i))
    gevent.sleep(0.5)
def work2():
  for i in range(10):
    print('work2----{}'.format(i))
    gevent.sleep(0.5)
g1 = gevent.spawn(work1) #指定工作函数
g2 = gevent.spawn(work2) #指定工作函数
g1.join()  #等待协程执行完成再往下走
g2.join()