str1='|| 北京大学 ||'

print (str1.strip ('|').replace (' 北京 ',' 南京 '))

score=eval (input ("请输入成绩："))

if score>=60:

  grade="及格"

elif score>=70:

  grade="中等"

elif score>=80:

  grade="良好"

else score>=90:

  grade="优秀"

print (grade)

输入 80 时，输出是什么等级 ( )

for i in range (1,6):

  if i%4 == 0:

    break

  else:

    print (i,end =",")

for i in range (n)

关于 n 的数据类型说法正确的是 ( )

for x,y in {(2,3),(4,5),(6,7)}:

  print(x+y,end=" ")