Python Pandas:将<class'tuple'>转换为datetime

Question

我有一个看起来像这样的DataFrame

         Sigma     JulianDay  
 0       -9.05  2.451545e+06 
 1      -10.99  2.451545e+06 
 2       -8.42  2.451546e+06 
 3       -8.92  2.451547e+06 
 4      -10.79  2.451547e+06
 5       -9.53  2.451548e+06

我想将列'JulianDay'转换为格里高利日期.为此,我使用了jdcal 1.3软件包和已定义的函数jd_to_date(jd)

d = df['JulianDay'].apply(jd_to_date)
df['GregDate'] = d

结果是:

        Sigma     JulianDay       GregDate
0       -9.05  2.451545e+06   (2000, 1, 1)
1      -10.99  2.451545e+06   (2000, 1, 1) 
2       -8.42  2.451546e+06   (2000, 1, 2)
3       -8.92  2.451547e+06   (2000, 1, 3)
4      -10.79  2.451547e+06   (2000, 1, 3)
5       -9.53  2.451548e+06   (2000, 1, 4)

输出还告诉我,我正在处理一个对象类型:

Name: JulianDay, dtype: object

我现在的问题是,我想将GregDate列转换为datetime,以便我能够将GregDate设置为索引.但是dtype:对象在尝试时给了我麻烦

df['GregDate'] = pd.to_datetime(d)

我收到错误:

TypeError: <class 'tuple'> is not convertible to datetime

那么,我如何首先将"元组"列转换为其他内容,以便我能够将其转换为日期时间？

谢谢

Answer 1

您可以创建新DataFrame的constructor,然后应用to_datetime,重要的是列名year,month以及day:

a = pd.DataFrame(df['GregDate'].values.tolist(), columns=['year','month','day'])
print (a)
   year  month  day
0  2000      1    1
1  2000      1    1
2  2000      1    2
3  2000      1    3
4  2000      1    3
5  2000      1    4

df.GregDate = pd.to_datetime(a)
print (df)
   Sigma  JulianDay   GregDate
0  -9.05  2451545.0 2000-01-01
1 -10.99  2451545.0 2000-01-01
2  -8.42  2451546.0 2000-01-02
3  -8.92  2451547.0 2000-01-03
4 -10.79  2451547.0 2000-01-03
5  -9.53  2451548.0 2000-01-04