python eventlet绿化和patch原理

import sys
import eventlet
# eventlet.monkey_patch()
 
httplib2 = eventlet.import_patched('httplib2')
print(httplib2)
print(httplib2.socket)
 
print("================")
for k,v in sys.modules.items():
  if "socket" in k:
    print(k, v)
 
 
# 打印内容
<module 'httplib2' from 'D:\\workspace\\venv\\xxx\\lib\\site-packages\\httplib2\\__init__.py'>
<module 'eventlet.green.socket' from 'D:\\workspace\\venv\\xxx\\lib\\site-packages\\eventlet\\green\\socket.py'>
================
_socket <module '_socket' from 'c:\\python\\python36\\DLLs\\_socket.pyd'>
socket <module 'socket' from 'c:\\python\\python36\\lib\\socket.py'>
__original_module_socket <module 'socket' from 'c:\\python\\python36\\lib\\socket.py'>
 
# 说明了什么？
绿化只是替换httplib2模块中的引用属性socket。并未改变sys.modules中的属性

from eventlet.green import socket

import eventlet
httplib2 = eventlet.import_patched('httplib2')
print(httplib2)
print(httplib2.socket)
 
# 打印
<module 'httplib2' from 'D:\\workspace\\venv\\autumn-secs\\lib\\site-packages\\httplib2\\__init__.py'>
<module 'eventlet.green.socket' from 'D:\\workspace\\venv\\autumn-secs\\lib\\site-packages\\eventlet\\green\\socket.py'>