Question

我是python 3的新手我必须从.csv文件中获取日期时间值并将其拆分为单独的日期和时间值列。

csv文件：

C1,C2,V2,Time_Stamp
0.1,1.3,-0.9,13/6/2017 14:42
0.1,1.2,-0.9,13/6/2017 14:42
0.1,1.3,-0.9,13/6/2017 14:42
0.1,1.3,-0.9,13/6/2017 14:42

最初，我在Time_Stamp下有这个：

运行后

输出：

timestamps = Data.Time_Stamp
for i in timestamps:
    dataobj = dt.datetime.strptime(i, "%d/%m/%Y %H:%M") #Time_Stamp datetime format - need set varibale to print
    print (dataobj) #Prints the following output

输出：

13/6/2017 14:42

13/6/2017 14:42

13/6/2017 14:42

13/6/2017 14:42

13/6/2017 14:42

根据上面的输出，它在一列中有日期和时间，我希望日期在不同的列中，时间在另一列中。

   13/6/2017 14:42    13/6/2017   14:42

   13/6/2017 14:42    13/6/2017   14:42

   13/6/2017 14:42    13/6/2017   14:42

   13/6/2017 14:42    13/6/2017   14:42

   13/6/2017 14:42    13/6/2017   14:42

我尝试了以下Splitting timestamp column into seperate date and time columns中的示例，但我无法获得类似的输出。

import pandas as pd
import csv 
import datetime as dt

print (row)

Data = pd.DataFrame.from_csv('csv_date.csv')
print (Data)

timestamps = Data.Time_Stamp
for i in timestamps:
    dataobj = datetime.strptime(i, "%d/%m/%Y %H:%M")

df['new_date'] = [i.date() for i in Data['Time_Stamp']]
df['new_time'] = [i.time() for i in Data['Time_Stamp']]

我遇到的错误：

AttributeError                            Traceback (most recent call last)
<ipython-input-137-ca9ed5c25ff2> in <module>()
----> 1 df['new_date'] = [i.date() for i in Data['Time_Stamp']]
      2 df['new_time'] = [i.time() for i in Data['Time_Stamp']]

<ipython-input-137-ca9ed5c25ff2> in <listcomp>(.0)
----> 1 df['new_date'] = [i.date() for i in Data['Time_Stamp']]
      2 df['new_time'] = [i.time() for i in Data['Time_Stamp']]

AttributeError: 'str' object has no attribute 'date'

Answer 1

阅读时，将pd.read_csv与parse_dates和infer_datetime_format一起用作True。

Data = pd.read_csv('csv_date.csv', parse_dates=['Time_Stamp'], infer_datetime_format=True)

接下来，您只需提取日期＆amp;时间：

Data['Date'] = Data.Time_Stamp.dt.date
Data['Time'] = Data.Time_Stamp.dt.time

Answer 2

Data = pd.DataFrame.from_csv('csv_date.csv')
Data['new_times'] = Data['Time_Stamp'].apply(lambda x:datetime.strptime(x, "%d/%m/%Y %H:%M"))

使用apply和lambda处理Dataframe

在csv中拆分日期时间以分隔日期和时间列

2 个答案: