用Python实现换行符转换的脚本的教程

 #!/usr/bin/env python   #2009-2011 dbzhang800   import os   import re   import os.path      def convert_line_endings(temp, mode):     if mode in ['u', 'p']: #unix, posix       temp = temp.replace('/r/n', '/n')       temp = temp.replace('/r', '/n')     elif mode == 'm':   #mac (before Mac OS 9)       temp = temp.replace('/r/n', '/r')       temp = temp.replace('/n', '/r')     elif mode == 'w':   #windows       temp = re.sub("/r(?!/n)|(?<!/r)/n", "/r/n", temp)     return temp      def convert_file(filename, args):     statinfo = None     with file(filename, 'rb+') as f:       data = f.read()       if '/0' in data and not args.force: #skip binary file... ?         print '%s is a binary file?, skip...' % filename         return       newdata = convert_line_endings(data, args.mode)       if (data != newdata):         statinfo = os.stat(filename) if args.keepdate else None         f.seek(0)         f.write(newdata)         f.truncate()     if statinfo:       os.utime(filename, (statinfo.st_atime, statinfo.st_mtime))     print filename      def walk_dir(d, args):     for root, dirs, files in os.walk(d):       for name in files:         convert_file(os.path.join(root, name), args)      if __name__ == '__main__':     import argparse     import sys     parser = argparse.ArgumentParser(description='Convert Line Ending')     parser.add_argument('filename', nargs='+', help='file names')     parser.add_argument('-r', dest='recursive', action='store_true',         help='walk through directory')     parser.add_argument('-m', dest='mode', default='d', choices='upwmd',         help='mode of the line ending')     parser.add_argument('-k', dest='keepdate', action='store_true',         help='keep output file date')     parser.add_argument('-f', dest='force', action='store_true',         help='force conversion of binary files')     args = parser.parse_args()     if args.mode == 'd':       args.mode = 'w' if sys.platform == 'win32' else 'p'        for filename in args.filename:       if os.path.isdir(filename):         if args.recursive:           walk_dir(filename, args)         else:           print '%s is a directory, skip...' % filename       elif os.path.exists(filename):         convert_file(filename, args)       else:         print '%s does not exist' % filename