python中用string.maketrans和translate巧妙替换字符串

   python中用string.maketrans和translate巧妙替换字符串

   将nginx日志中字符串 [2013-07-03T00:29:40-05:00] HTTP  格式化为："2013-07-03 00:29:40-05:00"

   整条日志如下：

92.82.22.46 - - [2013-07-03T00:29:40-05:00] "GET /images/mask_bg.png HTTP/1.1" 200 195 "http://www.chlinux.net/" "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)" "-"

   将[2013-07-03T00:29:40-05:00] 替换成为："2013-07-03 00:29:40-05:00"

   把[]换成"",然后把T替换成空格

做法如下：

>>> s='''92.82.22.46 - - [2013-07-03T00:29:40-05:00] "GET /images/mask_bg.png HTTP/1.1" 200 195 "http://www.chlinux.net/" "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)" "-"'''
>>> table = string.maketrans('[]','""')
>>> s.translate(table)
'92.82.22.46 - - "2013-07-03T00:29:40-05:00" "GET /images/mask_bg.png HTTP/1.1" 200 195 "http://www.chlinux.net/" "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)" "-"'
>>> s.translate(table).replace('T', ' ',1)#替换掉第一个T为空格
'92.82.22.46 - - "2013-07-03 00:29:40-05:00" "GET /images/mask_bg.png HTTP/1.1" 200 195 "http://www.chlinux.net/" "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)" "-"'
也可以这样：
>>> table = re.sub('\[|\]','"',s).replace('T', ' ',1)
>>>print table
'92.82.22.46 - - "2013-07-03 00:29:40-05:00" "GET /images/mask_bg.png HTTP/1.1" 200 195 "http://www.chlinux.net/" "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)" "-"'