Python简单小程序，请问怎样修改下面的代码使得循环次数等于学生人数

num = int(input("请输入学生人数："))
i = 0
name_list = []
source_list = []
while True:
name = input("请输入学生姓名：")
source = input("请输入学生成绩：")
while i <= num:
if not 0 == i - num:
break
i += 1
else:
print()
name = str(name)
source = int(source)
name_list.append(name)
source_list.append(source)
d = dict(zip(name_list, source_list))
source_sum = sum(d.values())
number = len(d)
print("平均分%s" % (source_sum / number))
stu_max = max(d.values())
max_name = list(d.keys())[list(d.values()).index(stu_max)]
print("最高分同学为姓名为：%s，成绩为：%d" % (max_name, stu_max))
stu_min = min(d.values())
min_name = list(d.keys())[list(d.values()).index(stu_min)]print("最低分同学为姓名为：%s，成绩为：%d" % (min_name, stu_min))

num = int(input("请输入学生人数："))
i = 0
name_list = []
source_list = []
while i < num:
    name = input("请输入学生姓名：")
    source = input("请输入学生成绩：")
    name = str(name)
    source = int(source)
    name_list.append(name)
    source_list.append(source)
    i += 1
d = dict(zip(name_list, source_list))
source_sum = sum(d.values())
number = len(d)
print("平均分%s" % (source_sum / number))
stu_max = max(d.values())
max_name = list(d.keys())[list(d.values()).index(stu_max)]
print("最高分同学为姓名为：%s，成绩为：%d" % (max_name, stu_max))
stu_min = min(d.values())
min_name = list(d.keys())[list(d.values()).index(stu_min)]print("最低分同学为姓名为：%s，成绩为：%d" % (min_name, stu_min))