Just ten minutes ago , In the Q & A area and qq The group posted this question ,qq A big guy of the group shared notes about this function , I put it in some order , And published in csdn On the platform

describe ：

build_opener(*handlers) Method is used to build a custom OpenerDirector object

Import ：

# python2
from urllib2 import build_opener
# python3
from urllib.request import build_opener

grammar ：

build.opener(handler1,handler2…)

Parameters ：

1. *handlers( Mandatory ) – Collection parameters （ Processor object or processor class ） It can be
   [ProxyHandler,UnknownHandler,HTTPHandler,HTTPDefaultErrorHandler,HTTPRedirectHandler,FTBHandler]

Return value ：

OpenerDiretop example – opener object