Pandas，格式日期从年月日到年月日

Question

我想把日期从dd/mm/yyyy改为MMM dd/yy。 ie15/04/2021到APR 15/21

我的Date列格式为object

我正在这样做： df['Date'] = pd.to_datetime(df['Date'], format='%MMM %DD/%YY')

但是我得到了ValueError: time data '15/04/2021' does not match format '%MMM %dd/%yy' (match)

任何帮助都将不胜感激

Answer 1

>>> import pandas as pd

>>> df = pd.DataFrame({'Date':['15/04/2021', '12/05/2021', '4/6/2021']})
>>> df
         Date
0  15/04/2021
1  12/05/2021
2    4/6/2021

>>> df['Date'] = pd.to_datetime(df['Date'])
>>> df
        Date
0 2021-04-15
1 2021-12-05
2 2021-04-06

>>> df['date_formated'] = df['Date'].dt.strftime('%b %d/%y').str.upper()
>>> df
        Date date_formated
0 2021-04-15     APR 15/21
1 2021-12-05     DEC 05/21
2 2021-04-06     APR 06/21

>>> df.info()
<class 'pandas.core.frame.DataFrame'>
RangeIndex: 3 entries, 0 to 2
Data columns (total 2 columns):
 #   Column         Non-Null Count  Dtype         
 -                         -         
 0   Date           3 non-null      datetime64[ns]
 1   date_formated  3 non-null      object        
dtypes: datetime64[ns](1), object(1)
memory usage: 176.0+ bytes

Answer 2

您需要将原始的Date列转换为datetime格式（默认情况下，熊猫将以字符串形式读取日期）。完成此操作后，只需更改显示格式

试试这个：

# Convert to datetime
df['Date'] = pd.to_datetime(df['Date'], format='%d/%m/%y')

# Solution for title: change display to 'MMM dd/y'
df['Date'] = df['Date'].dt.strftime('%b %d/%y').astype(str).str.upper()

# Solution for comment: change display to 'MMM dd y'
df['Date'] = df['date'].dt.strftime('%b %d %y').astype(str).str.upper()

Answer 3

试试-

df.loc['Date'] = pd.to_datetime(df.Date).dt.strftime('%b %d/%y').str.upper()