with open(r"C:\Users\86185\Desktop\book.txt",'r',encoding='UTF-16') as f:
    b=input("请输入要查询的人：")
    h=""
    for i in f:
        if b in i:
            g=i
            print("找到了")
            q=input("请输入想修改成的值：")
            i=q+"\n"
        h+=i
with open(r"C:\Users\86185\Desktop\book.txt",'w',encoding='UTF-16') as f:
    f.write(h)
# replace