http://www.pythonchallenge.com/pc/def/ocr.html
根据页面提示查看网页源代码,在最后:<!--
find rare characters in the mess below:
-->
<!--
%%$@_$^__#)^)&!_+]!*@&^}@[@%]()%+$&[(_@%+%$*^@$^!+]!&_#)_*}{}}!}_]$[%}@[{_@#_^{*
@##&{#&{&)*%(]{{([*}@[@&]+!!*{)!}{%+{))])[!^})+)$]#{*+^((@^@}$[**$&^{$!@#$%)!@(&
后面一大串特殊字符
将这一串复制,保存到一个文件/tmp/abc.txt下
>>>import re
>>>with open('/tmp/abc.txt','r') as f:
>>> text=f.read()
>>> "".join(re.findall("[a-zA-Z0-9]",text))
'equality'
输入:http://www.pythonchallenge.com/pc/def/equality.html
ok,level 3