Python 数据帧：计算特定日期值的出现次数并根据条件删除

Question

I am using python and pandas for my assignment. my Datafrmae looks something like this:

Date	Time	Business hours
2021/4/26	0800	NO
2021/4/26	0900	Yes
2021/4/26	1000	Yes

I want to figure out if the date was a holiday by counting how many yes and no there are on a specific date - if the count of yes is less then 7, then I would deem that date a Holiday and exclude it from my calculations by deleting it.

I was thinking of adding a holiday column with boolean value. Been looking all over for a solution online but falling short. Im pretty new to Python so i apologise if i said anything stupid

Answer 1

We can use transform here with groupby:

s = df["Business hours"].eq("Yes").groupby(df["Date"]).transform("Sum")
df[s >= 7]

Answer 2

Try groupby filter function:

def filter_rows(x):
    try:
        x['Business hours'].value_counts()['Yes'] >= 7
        return True
    except KeyError as e:
        return False
df = df.groupby('Date').filter(filter_rows)