使用Python和datetime将字符串转换为日期

Question

I have a column that contains stings in the form 'yyyymmdd' as below;

Start_date
20081201
20120823
20101210

I want to be able to convert these into actual dates and am looking at using datetime . From looking online I have managed to get to define both of the following functions.

def dateconvert(Start_date):
    dateconv = datetime.strptime(Start_date, '%Y%m%d').strftime('%m/%d/%Y')
    return  dateconv

def get_datetime(date_string):
    newdate = datetime.date(date_string[:3],date_string[4:6],date_string[6:8])
    return newdate

I have then tried applying these using the apply function as below

 Dates['Newdates'] = Dates['Start_date'].apply(get_datetime)

However I keep getting the following error

TypeError: 'long' object has no attribute '__getitem__'

Even though the values in the fields are Integers!

Answer 1

You need to cast the date to a string first.

import datetime as dt
dt.datetime.strptime(str(20081201), '%Y%m%d').strftime('%m/%d/%Y')

Will return

'12/01/2008'

Answer 2

The full solution I used was the following

import datetime as dt

def dateconvert(Start_date):
    Date_String = str(Start_date)
    dateconv = dt.datetime.strptime(Date_String, '%Y%m%d').strftime('%m/%d/%Y')
    return  dateconv

Dates['Newdates'] = Dates['Start_date'].apply(dateconvert)