How to add a name to a grouped column in pandas-CodePudding

Can someone please help with the following question: When I use a group by, the result I get a time_counts frame, but the new grouped column has no name. How do I give it a name?

import pandas as pd

def read_data():
    df = pd.read_csv("test.csv", usecols=['time', 'unix_time', 'name'])
    df['time'] = pd.to_datetime(df['time'])
    df['unix_time'] = (df['unix_time']).astype(int)


    time_counts = df.groupby(df['time'].dt.floor('S'))['time'].count()
    print(time_counts)


if __name__ == "__main__":
    read_data()

output is:

time
2022-12-15 08:00:18    1
2022-12-15 08:07:17    1
2022-12-15 08:12:09    1
2022-12-15 08:12:19    1
2022-12-15 08:13:04    1

desired output is :

time                   count
2022-12-15 08:00:18    1
2022-12-15 08:07:17    1
2022-12-15 08:12:09    1
2022-12-15 08:12:19    1
2022-12-15 08:13:04    1

data in csv is :

time                    unix_time       name
2022-12-15 08:00:18.034 1671091218034   apple
2022-12-15 08:07:17.376 1671091637376   apple
2022-12-15 08:12:09.648 1671091929648   apple
2022-12-15 08:12:19.320 1671091939320   apple
2022-12-15 08:13:04.623 1671091984623   apple

CodePudding user response：

You could do it like this,I did no changes except this line:

time_counts = df.groupby(df['time'].dt.floor('S'))['time'].count().reset_index(name='count')

                 time  count
0 2022-12-15 08:00:18      1
1 2022-12-15 08:07:17      1
2 2022-12-15 08:12:09      1
3 2022-12-15 08:12:19      1
4 2022-12-15 08:13:04      1

Note that the output you created was a pd.Series, with my added content time_counts is a pd.DataFrame.

CodePudding user response：

Using .agg() you can set column name and aggregate:

time_counts = df.groupby(df["time"].dt.floor("S")).agg(count=("time", "count")).reset_index()
print(time_counts)

Output:

                 time  count
0 2022-12-15 08:00:18      1
1 2022-12-15 08:07:17      1
2 2022-12-15 08:12:09      1
3 2022-12-15 08:12:19      1
4 2022-12-15 08:13:04      1