按分钟，小时，天，月和年分组？

Question

I'm searching a solution for my problem, but I can't find. So I'm hoping you can help me.

Problem:

I want to count the number of tweets in a minute.

Dataset:

    time                       sentiment
0   2018-05-02 14:28:59.281     0.8104
1   2018-05-02 14:29:03.540     0.6536
2   2018-05-02 14:29:09.570     0.0000
3   2018-05-02 14:29:10.445     0.0000
4   2018-05-02 14:29:22.245     0.0000
5   2018-05-02 14:29:23.349     0.4389
6   2018-05-02 14:29:28.329     0.2732
7   2018-05-02 14:29:30.410     0.2732
8   2018-05-02 14:29:46.122     0.0000
9   2018-05-02 14:29:53.194     -0.5562

I want to count the numbers of tweets in a minute and then plot them. But when I use groupby().count() this deletes the day, month, and year.

I got back all tweets for minute 1, but I want to get the number of tweets for 14:29 2018-05-02 and then number of tweets for 14:30 2018-05-02 .

Answer 1

With a pandas dataframe you can groupby with a period of a minute and count . You need to make sure that time is a datetime field, eg:

df.time = pd.to_datetime(df.time)

Then simply:

df.groupby(df.time.dt.to_period('Min')).count()