找不到变量错误

Question

脚本.py

code = open("my_solution.py").read()
input_stream = StringIO(input_file)
sys.stdin = input_stream
output_stream = sys.stdout = StringIO()
exec(code)

my_solution.py

for _ in range(int(input())):
    n = int(input())
    ar = list(map(int, input().split()))
    y = min(ar)
    print(sum([x - y for x in ar if x > y])) 

输出：

exec(code) File "<string>", line 6, in <module> File "<string>", line 6, in <listcomp> NameError: name 'y' is not defined

为什么会发生这种事？