greenlet手動切換協程
from greenlet import greenlet

def tes_1():
    print(12)
    gr2.switch()#協程手動切換
    print(34)
    gr2.switch()#協程切換

def tes_2():
    print(56)
    gr1.switch()#協程切換
    print(78

gevent自動切換協程
 import gevent
 
 def foo():
     print("running in foo")
     gevent.sleep(2) #IO阻塞2秒 自動切換下一個協程
     print('Explict context switch to foo again')
 def bar():
     
 
print("Explicit精確的 context上下文切換 to bar")
     gevent.sleep(1)#IO阻塞1秒
     print('Implicit context switch back to bar')
 def func3():
     print("running func3")
     gevent.sleep(0)#IO不阻塞，釋放 就先執行下面程式碼
     print("running func3 again"
 
)
 
 gevent.joinall([
     gevent.spawn(foo),#生成協程
     gevent.spawn(bar),
     gevent.spawn(func3),
 ])