Python删除Java源文件中全部注释的实现方法

#!D:\Python32
# 过滤JAVA程序中的注释
# 如果字符串中有注释符号的话会有问题。
import os
import re
import io
# 改这个目录！！！
top_dir = "E:\\java_comments_trim\\";
# 状态
S_INIT       = 0;
S_SLASH       = 1;
S_BLOCK_COMMENT   = 2;
S_BLOCK_COMMENT_DOT = 3;
S_LINE_COMMENT   = 4;
S_STR        = 5;
S_STR_ESCAPE    = 6;
def trim_dir(path):
 print("目录：" + path);
 for root, dirs, files in os.walk(path):
  for name in files:
   trim_file(os.path.join(root, name))
  #for name in dirs:
   #trim_dir(os.path.join(root, name))
def trim_file(path):
 print("文件：" + path);
 if re.match(".*java{1}quot;, path):
  print(" 处理");
 else:
  print(" 忽略");
  return;
 bak_file = path + ".bak";
 os.rename(path, bak_file);
 fp_src = open(bak_file);
 fp_dst = open(path, 'w');
 state = S_INIT;
 for line in fp_src.readlines():
  for c in line:
   if state == S_INIT:
    if c == '/':
     state = S_SLASH;
    elif c == '"''"':
     state = S_STR;
     fp_dst.write(c);
    else:
     fp_dst.write(c);
   elif state == S_SLASH:
    if c == '*':
     state = S_BLOCK_COMMENT;
    elif c == '/':
     state = S_LINE_COMMENT;
    else:
     fp_dst.write('/');
     fp_dst.write(c);
   elif state == S_BLOCK_COMMENT:
    if c == '*':
     state = S_BLOCK_COMMENT_DOT;
   elif state == S_BLOCK_COMMENT_DOT:
    if c == '/':
     state = S_INIT;
    else:
     state = S_BLOCK_COMMENT;
   elif state == S_LINE_COMMENT:
    if c == '\n':
     state = S_INIT;
   elif state == S_STR:
    if c == '\\':
     state = S_STR_ESCAPE;
    elif c == '"':
     state = S_INIT;
    fp_dst.write(c);
   elif state == S_STR_ESCAPE:
    # 这里未完全实现全部序列，如\oNNN \xHH \u1234 \U12345678，但没影响
    state = S_STR;
    fp_dst.write(c);
 fp_src.close();
 fp_dst.close();
trim_dir(top_dir);