报错：ValueError: I/O operation on closed file.
原因为代码结构上提示行未正确缩进，导致程序尝试修改已经关闭的文件，在用with语句时要注意此问题。代码中倒数第三行若没有缩进与倒数第二行平齐就会出现此问题。
def exchange(f_name): list3=[] with open(f_name,mode="r",encoding="UTF-8") as f1, open(f_name+"_副本",mode="w",encoding="UTF-8") as f2: for line2 in f1.readlines(): list3.append(line2) seq=["%nprocshared=28n","%mem=40GBn" "%chk=c3v.chkn","#p sp b3lyp/6-31g(d)" ,"c3v"] f2.writelines(seq) f2.writelines(list3[4:]) os.remove(f_name) os.rename(f_name+"_副本",f_name)'''
词条：line = line.strip()
strip可以使读取列表时去除str的首尾空行，也会去除n这样的换行符号