有哪位能帮我看一下代码？

from tkinter import Tk,simpledialog,messagebox
def read_from_file():
    with open('国家、首都名.txt')as file:
        for line in file:
            line=line.rstrip('\n')
            country,city=line.rstrip('/')
            the_world[country]=city
def write_to_file(country_name,city_name):
    with open('国家、首都名.txt','a') as file:
        file.write('\n'+country_name+'/'+city_name)
print('咨询专家 - 世界首都')
root=Tk()
root.withdraw()
the_world={}
read_from_file()
while True:
    query_country=simpledialog.askstring('国家','输入国家名称：')
    if query_country in the_world:
        result=the_world[query_country]
        messagebox.showinfo('回答','查询'+query_country+'的首都是'+result+'!')
    else:
        new_city=simpledialog.askstring('教我','我不知道！'+query_country+'的首都是哪里'+'?')
        the_world[query_country]=new_city
        write_to_file(query_country,new_city)
root.mainloop()

运行代码结果：

咨询专家 - 世界首都
Traceback (most recent call last):
  File "D:\方嘉铭 编程\请教专家.py", line 15, in <module>
    read_from_file()
  File "D:\方嘉铭 编程\请教专家.py", line 4, in read_from_file
    for line in file:
UnicodeDecodeError: 'gbk' codec can't decode byte 0x8c in position 15: illegal multibyte sequence

with open('国家、首都名.txt', encoding='utf8')as file