使用python读取指定目录下的源代码并将内容复制到同一新文件中

#coding=utf-8
import os;

rootDir = "D:\\JavaWorkspace\\WebRoot\\";
txtFile = "E:\\txtFile.txt";

targetFile = open(txtFile,'a');

def getAllFiles(dir):
for lists in os.listdir(dir):
path = os.path.join(dir,lists);
if os.path.isdir(path):
getAllFiles(path);
else:
writeToFile(path);
print path[path.rfind("\\")+1:];

def writeToFile(dir):
fromFile = open(dir);
targetFile.write(dir[dir.rfind("\\")+1:] + "\n\n");
targetFile.write(fromFile.read());
targetFile.write("\n\n");
fromFile.close();

getAllFiles(rootDir);