Python2 转Python3

1. 工具命令

* python2
    * python/pip/pydoc  
* python3
    * python3/pip3/pydoc3

2. 语法

1. exception

   python3
       
   try 
       # code here 
   except KeyError as e:
       pass
   

2. print

   python2:
   print "abc"
   
   python3:
   print("abc")
   

3. urllib

   python3统一了 urllib 和urllib2

   python2 :
   import urllib ,urllib2 
   
   python3 :
   import urllib
   import urllib.parse, urllib.request
   
   urllib.parse.urlenc