from greenlet import greenlet
import time
def work1():
    while True:
        print("正在执行work1.....")
        time.sleep(0.5)
        g2.switch()

def work2():
    while True:
        print("正在执行work2.....")
        time.sleep(0.5)
        g1.switch()
if __name__=='__main__':
    g1=greenlet(work1)
    g2=greenlet(work2)
    g1.switch()