Question

我有一个df，是用户访问数据的时间序列

UserID     Access Date
a          10/01/2019
b          10/01/2019
c          10/01/2019
a          10/02/2019
b          10/02/2019 
d          10/02/2019
e          10/03/2019
f          10/03/2019
a          10/03/2019
b          10/03/2019
a          10/04/2019
b          10/04/2019
c          10/05/2019

我还有另一个df列出了日期，并且我想汇总过去3天中唯一出现的UserID。预期的输出如下所示：

Date         Past_3_days_unique_count
10/01/2019   NaN
10/02/2019   NaN
10/03/2019   6
10/04/2019   5
10/04/2019   5

我将如何实现这一目标？

Answer 1

这非常简单-让我通过以下代码段及其注释向您介绍。

import pandas as pd
import numpy as np

# Generate some dates
dates = pd.date_range("01-01-2016", "01-10-2016", freq="6H")

# Generate some user ids
ids = np.random.randint(1, 5, len(dates))

df = pd.DataFrame({"id": ids, "date": dates})

# Collect unique IDs for each day
q = df.groupby(df["date"].dt.to_period("D"))["id"].nunique()

# Grab the rolling sum over 3 previous days which is what we wanted
q.rolling(3).sum()

Answer 2

根据文档使用pandas group非常好

Python：过去3天计算唯一价值

2 个答案: