多任务5-协程（IO密集型适用）--gevent完成多任务及monkey补丁

代码：

 import gevent

 def f1(n):
     for i in range(n):
         print(gevent.getcurrent(),i)
         gevent.sleep(1)

 def f2(n):
     for i in range(n):
         print(gevent.getcurrent(),i)
         gevent.sleep(0.1)

 def f3(n):
     for i in range(n):
         print(gevent.getcurrent(),i)
         gevent.sleep(0.2)

 print("---1---")
 # gevent比greenlet好的地方是，遇到sleep自动切换，但是不支持time.sleep（），支持gevent.sleep()
 # 不止是sleep，但凡延时或者堵塞的东西全要换成gevent里面的
 g1 = gevent.spawn(f1,5)
 print("---2---")
 g2 = gevent.spawn(f2,5)
 print("---3---")
 g3 = gevent.spawn(f3,5)
 print("---4---")
 g1.join()
 g2.join()
 g3.join()

结果：

---1---
---2---
---3---
---4---
<Greenlet at 0x1ba58dbc648: f1(5)> 0
<Greenlet at 0x1ba58dbc948: f2(5)> 0
<Greenlet at 0x1ba58dbca48: f3(5)> 0
<Greenlet at 0x1ba58dbc948: f2(5)> 1
<Greenlet at 0x1ba58dbca48: f3(5)> 1
<Greenlet at 0x1ba58dbc948: f2(5)> 2
<Greenlet at 0x1ba58dbc948: f2(5)> 3
<Greenlet at 0x1ba58dbca48: f3(5)> 2
<Greenlet at 0x1ba58dbc948: f2(5)> 4
<Greenlet at 0x1ba58dbca48: f3(5)> 3
<Greenlet at 0x1ba58dbca48: f3(5)> 4
<Greenlet at 0x1ba58dbc648: f1(5)> 1
<Greenlet at 0x1ba58dbc648: f1(5)> 2
<Greenlet at 0x1ba58dbc648: f1(5)> 3
<Greenlet at 0x1ba58dbc648: f1(5)> 4

　　

这种比较麻烦，如果源代码里面用到time.sleep()或者socket中的堵塞，一个一个改会很麻烦，所以有了gevent的补丁

代码：

 import gevent
 import time
 from gevent import monkey

 monkey.patch_all()

 def f1(n):
     for i in range(n):
         print(gevent.getcurrent(),i)
         time.sleep(1)

 def f2(n):
     for i in range(n):
         print(gevent.getcurrent(),i)
         time.sleep(0.1)

 def f3(n):
     for i in range(n):
         print(gevent.getcurrent(),i)
         time.sleep(0.2)

 # print("---1---")
 # # gevent比greenlet好的地方是，遇到sleep自动切换，但是不支持time.sleep（），支持gevent.sleep()
 # # 不止是sleep，但凡延时或者堵塞的东西全要换成gevent里面的
 # g1 = gevent.spawn(f1,5)
 # print("---2---")
 # g2 = gevent.spawn(f2,5)
 # print("---3---")
 # g3 = gevent.spawn(f3,5)
 # print("---4---")
 # g1.join()
 # g2.join()
 # g3.join()
 # 一个一个join()很麻烦，可以放到joinall()的列表中
 gevent.joinall([
     gevent.spawn(f1,5),
     gevent.spawn(f2,5),
     gevent.spawn(f3,5)

 ])

结果不变：

<Greenlet at 0x1a159007048: f1(5)> 0
<Greenlet at 0x1a159007248: f2(5)> 0
<Greenlet at 0x1a159007348: f3(5)> 0
<Greenlet at 0x1a159007248: f2(5)> 1
<Greenlet at 0x1a159007348: f3(5)> 1
<Greenlet at 0x1a159007248: f2(5)> 2
<Greenlet at 0x1a159007248: f2(5)> 3
<Greenlet at 0x1a159007348: f3(5)> 2
<Greenlet at 0x1a159007248: f2(5)> 4
<Greenlet at 0x1a159007348: f3(5)> 3
<Greenlet at 0x1a159007348: f3(5)> 4
<Greenlet at 0x1a159007048: f1(5)> 1
<Greenlet at 0x1a159007048: f1(5)> 2
<Greenlet at 0x1a159007048: f1(5)> 3
<Greenlet at 0x1a159007048: f1(5)> 4