python排班问题？

题干：有如下排班表，现增加条件，让钱和周不能在同一天值班（即他们俩不能同时在周一和周六值班。不允许直接修改字典）。怎么在代码中加条件？

```python
from itertools import permutations

week_list = ["星期一", "星期二", "星期三", "星期四", "星期五", "星期六", "星期日"]
#字典记的是每个人能上班的时间
dic = {
    "赵": ["星期二", "星期四"],
    "钱": ["星期一", "星期六"],
    "孙": ["星期三", "星期日"],
    "李": ["星期五"],
    "周": ["星期一", "星期四", "星期六"],
    "吴": ["星期二", "星期五"],
    "陈": ["星期三", "星期六", "星期日"],
}

for names in permutations(dic):
    res = []
    for i, j in enumerate(names):
        if week_list[i] not in dic[j]:
            break
        res.append(f"{week_list[i]}: {j}")
    else:
        print(*res, sep=", ")

```

from itertools import permutations
 
week_list = ["星期一", "星期二", "星期三", "星期四", "星期五", "星期六", "星期日"]
#字典记的是每个人能上班的时间
dic = {
    "赵": ["星期二", "星期四"],
    "钱": ["星期一", "星期六"],
    "孙": ["星期三", "星期日"],
    "李": ["星期五"],
    "周": ["星期一", "星期四", "星期六"],
    "吴": ["星期二", "星期五"],
    "陈": ["星期三", "星期六", "星期日"],
}

for names in permutations(dic):
    res = []
    for i, j in enumerate(names):
        if week_list[i] not in dic[j]:
            break
        res.append(f"{week_list[i]}: {j}")
        # 判断周和钱是否都在同一天值班
        if j == "周" and week_list[i] in dic["钱"]:
            break
        if j == "钱" and week_list[i] in dic["周"]:
            break
    else:
        print(res)