代码：
1 import gevent
2
3
4 def f1(n):
5 for i in range(n):
6 print(gevent.getcurrent(),i)
7 gevent.sleep(1)
8
9 def f2(n):
10 for i in range(n):
11 print(gevent.getcurrent(),i)
12 gevent.sleep(0.1)
13
14
15 def f3(n):
16 for i in range(n):
17 print(gevent.getcurrent(),i)
18 gevent.sleep(0.2)
19
20
21 print("---1---")
22 # 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()
23 # 不止是sleep，但凡延时或者堵塞的东西全要换成gevent里面的
24 g1 = gevent.spawn(f1,5)
25 print("---2---")
26 g2 = gevent.spawn(f2,5)
27 print("---3---")
28 g3 = gevent.spawn(f3,5)
29 print("---4---")
30 g1.join()
31 g2.join()
32 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：
1 import gevent
2 import time
3 from gevent import monkey
4
5
6 monkey.patch_all()
7
8 def f1(n):
9 for i in range(n):
10 print(gevent.getcurrent(),i)
11 time.sleep(1)
12
13
14 def f2(n):
15 for i in range(n):
16 print(gevent.getcurrent(),i)
17 time.sleep(0.1)
18
19
20 def f3(n):
21 for i in range(n):
22 print(gevent.getcurrent(),i)
23 time.sleep(0.2)
24
25
26 # print("---1---")
27 # # 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()
28 # # 不止是sleep，但凡延时或者堵塞的东西全要换成gevent里面的
29 # g1 = gevent.spawn(f1,5)
30 # print("---2---")
31 # g2 = gevent.spawn(f2,5)
32 # print("---3---")
33 # g3 = gevent.spawn(f3,5)
34 # print("---4---")
35 # g1.join()
36 # g2.join()
37 # g3.join()
38 # 一个一个join()很麻烦，可以放到joinall()的列表中
39 gevent.joinall([
40 gevent.spawn(f1,5),
41 gevent.spawn(f2,5),
42 gevent.spawn(f3,5)
43
44 ])
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