2to3.py的初次探讨
1、安装的位置： {PYTHON安装目录}/Tools/Scripts/2to3.py
2、作用：将python2的代码转换为Python3的代码
3、使用说明：
使用python命令进行查看>python C:\Python34\Tools\Scripts\2to3.py -h
Usage: 2to3 [options] file|dir ...
Options:
-h, --help show this help message and exit
-d, --doctests_only Fix up doctests only
-f FIX, --fix=FIX Each FIX specifies a transformation; default: all
-j PROCESSES, --processes=PROCESSES Run 2to3 concurrently
-x NOFIX, --nofix=NOFIX Prevent a transformation from being run
-l, --list-fixes List available transformations
-p, --print-function Modify the grammar so that print() is a function
-v, --verbose More verbose logging
--no-diffs Don't show diffs of the refactoring
-w, --write Write back modified files
-n, --nobackups Don't write backups for modified files
-o OUTPUT_DIR, --output-dir=OUTPUT_DIR
Put output files in this directory instead of
overwriting the input files. Requires -n.
-W, --write-unchanged-files
Also write files even if no changes were required
(useful with --output-dir); implies -w.
--add-suffix=ADD_SUFFIX
Append this string to all output filenames. Requires
-n if non-empty. ex: --add-suffix='3' will generate
.py3 files.
例子：
在D盘新建了一个python2.7的代码，p2.py：
print "Hello,World!" raw_input()
使用2to3.pyh进行转换，进入源代码目录，D:\>python C:\Python34\Tools\Scripts\2to3.py -w p2.py
print ("Hello,World!")
input()
转换后，源目录中出现的两个文件：
转化后的p2.py以及转化之前的p2.py.bak
总结：2to3.py将python2的代码自动转化为Python3的代码