批量替换文件夹下*.py文件里面的print "*"

  批量替换文件夹下*.py文件里面的print "*" -->print("*")
#批量替换选定文件夹或文件的print " "函数改print()  代码如下：
import os, re,tkinter
from tkinter import filedialog
if __name__=='__main__':
    work_dir=filedialog.askdirectory()  
    for parent, dirnames, filenames in os.walk(work_dir,  followlinks=True):
        for filename in filenames:
            if filename.find(".py")>0:
                file_path = os.path.join(parent, filename)
                file = open(file_path,"r ",encoding='UTF-8')
                sent=""
                for line in file.readlines():
                    line = re.sub(u"print[^\(](.*?);?$[^\)]",  u"print (\\1)", line)
                    sent=sent "\n" line
                file.close()
                file = open(file_path,"w",encoding='UTF-8')
                file.write(sent[1:])
                file.close()