Python从csv中读取日期和时间

Question

我的数据是这样的:

GIdx,Date,num,Time
1,11/28/2012,20,10:05:50
1,11/28/2012,20,10:05:50
2,11/28/2012,20,10:09:24
2,11/28/2012,20,10:09:24
2,11/28/2012,20,10:09:25
2,11/28/2012,20,10:09:25
2,11/28/2012,20,10:09:26
3,11/28/2012,20,10:09:34
3,11/28/2012,20,10:09:34

我尝试读取列日期作为datetime和列时间作为time但是当我检查他们的类型时，我得到Series:

type(df['Date'])
class pandas.core.series.Series
type(df_original['Time'])
class pandas.core.series.Series

我这样做了:

df=pd.read_csv(filename,sep=",", header = 0, na_values=['NA'])

Answer 1

您可以在read_csv中添加parse_dates参数，其中dates和times为列:

import pandas as pd
import io
temp=u"""GIdx,Date,num,Time
1,11/28/2012,20,10:05:50
1,11/28/2012,20,10:05:50
2,11/28/2012,20,10:09:24
2,11/28/2012,20,10:09:24
2,11/28/2012,20,10:09:25
2,11/28/2012,20,10:09:25
2,11/28/2012,20,10:09:26
3,11/28/2012,20,10:09:34
3,11/28/2012,20,10:09:34"""
#after testing replace io.StringIO(temp) to filename
df = pd.read_csv(io.StringIO(temp), parse_dates=[['Date','Time']])

print (df)
            Date_Time  GIdx  num
0 2012-11-28 10:05:50     1   20
1 2012-11-28 10:05:50     1   20
2 2012-11-28 10:09:24     2   20
3 2012-11-28 10:09:24     2   20
4 2012-11-28 10:09:25     2   20
5 2012-11-28 10:09:25     2   20
6 2012-11-28 10:09:26     2   20
7 2012-11-28 10:09:34     3   20
8 2012-11-28 10:09:34     3   20
print (df.dtypes)
Date_Time    datetime64[ns]
GIdx                  int64
num                   int64
dtype: object

您可以省略参数sep=",", header = 0和na_values=['NA']，因为默认情况下有:

df=pd.read_csv(filename,sep=",", header = 0, na_values=['NA'])

df=pd.read_csv(filename)