关于如何在python中打印出堆栈的log

#!/usr/bin/env pythonimport sysdef showStack(framenum):    for num in range(framenum):        frame = sys._getframe(num)    print"funname = %s, file/line = %s:%s" %(frame.f_code.co_name, frame.f_code.co_filename, frame.f_lineno)def func():    showStack(3)def main():    func()if __name__ == '__main__':    main()

文件名命名为showstack.py，在py下运行
./showstack.py
若权限不够，则chomd 755 showstack.py