在python pandas中，如何将此格式化的日期字符串转换为datetime

Question

I have tried several ways of using to_datetime , but so far I can only get it to return the dtype as "object"

pd.to_datetime(pd.Series(['28Dec2013 19:23:15']),dayfirst=True)

The return from this command is:

0    28Dec2013 19:23:15
dtype: object

Answer 1

You can pass a format parameter to the to_datetime function.

>>> import pandas as pd
>>> df = pd.to_datetime(pd.Series(['28Dec2013 19:23:15']),format="%d%b%Y %H:%M:%S",dayfirst=True)
>>> df
0   2013-12-28 19:23:15
dtype: datetime64[ns]

Answer 2

In case you need to convert existing columns in a dataframe here the solution using a helper function conv and the apply method.

import datetime
import pandas as pd

def conv(x):
    return datetime.datetime.strptime(x, '%d%b%Y %H:%M:%S')

series = pd.Series(['28Dec2013 19:23:15'])
converted = series.apply(conv)

0   2013-12-28 19:23:15
dtype: datetime64[ns]

Answer 3

Pandas does not recognize that datetime format.

>>> pd.to_datetime(Series(['28Dec2013 19:23:15']))
0    28Dec2013 19:23:15
dtype: object
>>> pd.to_datetime(Series(['28 Dec 2013 19:23:15']))
0   2013-12-28 19:23:15
dtype: datetime64[ns]

You will need to parse the strings you are feeding into the Series. Regular expressions will likely be a good solution for this.