python脚本替换指定行

工作中需要迁移代码，并把原来的日志系统更新到现在的格式，原来获取log的格式是

AuctionPoolLoggerUtil.getLogger()

现在获取log的格式是：

LoggerFactory.getLogger(XXXXX.class)

这里的XXXXX需要替换为当前的类名。如果这样的java文件不多还好，可以一个个人肉替换。一旦这样的文件很多，特别是迁移过来大量的文件时，你就会发现简直是一场灾难。其实我们发现上面的工作很多是机械单调的。ide中的替换功能不能做到的是把XXXXX替换成当前的类名。而python很容易处理文本，利用正则表达式可以比较方便的拿到类名，然后替换掉xxxxx就可以了。

import fileinput
import os
import re

__author__ = 'ykdsg'

packDir='/Users/ykdsg/svn_workspace/auctionplatform/misc_refactory/auctionplatform/ap-biz/src/main/java/com/yk/misccenter'
#查找class name
findClassNameP=re.compile(r"(?<=class\s)\w*")
findXP=re.compile(r"XXXXX")

def processDirectory(args,dirname,filenames):
# print 'Directory',dirname
for filename in filenames:

if os.path.splitext(filename)[1]=='.java':
# print 'file',filename
fullFileUrl=dirname+ "/"+filename
fileObj=open(fullFileUrl)
className=''
# Optional in-place filtering: if the keyword argument inplace=1 is passed to fileinput.input()  or to
# the FileInput constructor, the file is moved to a backup file and standard output is directed  to the
# input file (if a file of the same name as the backup file already exists, it will be replaced silently)
# .  This makes it possible to write a filter that rewrites its input file in place.  If the backup
# parameter is given (typically as backup='.<some extension>'), it specifies the extension  for the
# backup file, and the backup file remains around; by default, the extension is '.bak' and it is deleted
#  when the output file is closed. In-place filtering is disabled when standard input is read.
for line in fileinput.input(fullFileUrl, inplace=1):
matchClass = findClassNameP.search(line)
if matchClass:
className = matchClass.group()
matchX=findXP.search(line)
if matchX:
#print 后面需要有, 否则会出现多余的空行
print line.replace('XXXXX',className),
else:
print line,

def search():
os.path.walk(packDir,processDirectory,None)

if __name__ == '__main__':
search()

上面的脚本中大部分是fileinput.input的注释，就是说了inplace=1其实就是把源文件的内容放到缓存区，然后直接将内容写入源文件

findClassNameP 是查找class name的正则表达式，上面的逻辑就是对文件逐行分析，拿到class name。然后再分析当前行是否有xxxxx，有的话就用class name 替换，没有的话就原行输出。