为什么总是提示我fi.close()语句出错？

fi = open("score.csv","r")
fo = open("avg-score.txt","w")
ls = {}
x = []
sum = 0
for line in fi:
if line[0] == "课":
continue
x = line.strip(" ").split(",")[1:4]
sum = sum(x)/len(x)
d = {line.strip(" ").split(",")[0]:sum}
ls.update(d)
lis = list(ls.items())
for i in len(lis):
fo.write("{}:{}\n".format(lis[i][0],lis[i][1])
fi.close()
fo.close()

CSV文件的读写操作要用到csv模块的哈！你试试看下面代码能不能运行出来呢？
还有就是需要注意一下，打开文件最好确定一下编码格式encoding！
代码的缩进参照你写的改一下，不保证正确，你复制过来的代码没有缩进哈！

import csv
fi = open("score.csv","r",encoding="utf8")
reader = csv.reader(fi)

fo = open("avg-score.txt","w",encoding="utf8")
ls = {}
x = []
sum = 0
for line in reader:
    if line[0] == "课":
        continue
    x = line.strip(" ").split(",")[1:4]
    sum = sum(x)/len(x)
    
d = {line.strip(" ").split(",")[0]:sum}
ls.update(d)
lis = list(ls.items())

for i in len(lis):
    fo.write("{}:{}\n".format(lis[i][0],lis[i][1]))
             
fi.close()
fo.close()

代码中问题比较多， 一是读取的数据行没有对回车进行处理，二是对每行字符串形式数据没有转换为可计算的数值，三是使用了内置函数名sum做变量名，相应作一下修改即可，修改代码如下，经测试可以解决你的问题：

fi = open("score.csv", "r",encoding='utf-8')
fo = open("avg-score.txt", "w", encoding='utf-8')
ls = {}
x = []
sums = 0
for line in fi:
    if line[0] == "课":
        continue
    x = [float(s.strip()) for s in line.strip(" ").split(",")[1:4]]
    sums = sum(x)/len(x)
    d = {line.strip(" ").split(",")[0]: sums}
    ls.update(d)
lis = list(ls.items())
for i in range(len(lis)):
    fo.write("{}:{:.2f}\n".format(lis[i][0], lis[i][1]))
fi.close()
fo.close()

如有帮助，请点我回答右上方的采纳按钮采纳支持一下。

fclose(fi);
fclose(fo);