如何使用 linux/python 在 CSV 文件中创建派生列？

Question

我有一个包含以下各列的 CSV（示例）文件

PC_name,Time,Plant,Section,PC_value
35901052,2017-08-01 05:50,MIYAKONOJO,MIYAKONOJO_05,0.000
35901052,2017-08-01 05:51,MIYAKONOJO,MIYAKONOJO_05,0.000
35901052,2017-08-01 05:56,MIYAKONOJO,MIYAKONOJO_05,0.000
35901052,2017-08-01 06:01,MIYAKONOJO,MIYAKONOJO_05,0.000
35901052,2017-08-01 06:06,MIYAKONOJO,MIYAKONOJO_05,0.000

我想要一个基于“Time”列的新列“New”，如下所述

如果我的时间戳范围在 6pm(18:00) 到 6am(06:00) 之间，那么该值应该是“晚上" else "白天"

示例输出：

PC_name,Time,Plant,Section,PC_value,New
35901052,2017-08-01 05:50,MIYAKONOJO,MIYAKONOJO_05,0.000,Night
35901052,2017-08-01 05:51,MIYAKONOJO,MIYAKONOJO_05,0.000,Night
35901052,2017-08-01 05:56,MIYAKONOJO,MIYAKONOJO_05,0.000,Night
35901052,2017-08-01 06:01,MIYAKONOJO,MIYAKONOJO_05,0.000,Day
35901052,2017-08-01 06:06,MIYAKONOJO,MIYAKONOJO_05,0.000,Day

Answer 1

如果您可以使用 pandas 和 numpy，请使用 numpy.where and pandas.Series.dt.hour

执行以下操作

df=pd.read_csv('filename.csv',parse_dates=['Time'])
df['New'] = np.where((df.Time.dt.hour > 5) & (df.Time.dt.hour <18),'Day','Night')

df>>
    PC_name                Time       Plant        Section  PC_value    New
0  35901052 2017-08-01 05:50:00  MIYAKONOJO  MIYAKONOJO_05       0.0  Night
1  35901052 2017-08-01 05:51:00  MIYAKONOJO  MIYAKONOJO_05       0.0  Night
2  35901052 2017-08-01 05:56:00  MIYAKONOJO  MIYAKONOJO_05       0.0  Night
3  35901052 2017-08-01 06:01:00  MIYAKONOJO  MIYAKONOJO_05       0.0    Day
4  35901052 2017-08-01 06:06:00  MIYAKONOJO  MIYAKONOJO_05       0.0    Day

df.to_csv('New_filename.csv')

Answer 2

您可以将系列转换为日期时间并提取小时。然后将其映射到值

df["Time"] = pd.to_datetime(df["Time"])
df["New"] = df["Time"].dt.hour.map({hour: "Night" if 18 < hour or hour < 6 else "Day" for hour in range(23)})

输出：

>>> df
    PC_name                Time       Plant        Section  PC_value    New
0  35901052 2017-08-01 05:50:00  MIYAKONOJO  MIYAKONOJO_05       0.0  Night
1  35901052 2017-08-01 05:51:00  MIYAKONOJO  MIYAKONOJO_05       0.0  Night
2  35901052 2017-08-01 05:56:00  MIYAKONOJO  MIYAKONOJO_05       0.0  Night
3  35901052 2017-08-01 06:01:00  MIYAKONOJO  MIYAKONOJO_05       0.0    Day
4  35901052 2017-08-01 06:06:00  MIYAKONOJO  MIYAKONOJO_05       0.0    Day

如何使用 linux/python 在 CSV 文件中创建派生列？

How to create a derived column in a CSV file using linux/python?

python

linux

csv

derived-column