[问题求助] [已解决]请教Python正则表达式替换大小写字母，数字和特殊字符

#!/usr/bin/env python
# encoding: utf-8
import re
file1 = open('1.txt', 'r')
txt = file1.read()
reg = re.compile(r'[\da-z特殊字符]', re.I)
txt = reg.sub('', txt)
file2 = open('2.txt','w')
file2.write(txt)
file1.close()
file2.close()
print "完成"COPY