How To Do Groupby In Pandas With Part Of Date String?

Date Description 0 6/09/2012 Amazon 1 6/09/2012 iTunes 2 6/08/2012 iTunes 3 6/08/2012 Building 4 6/08/2012 Slicehost I have a DataFrame like the

Solution 1:

df.groupby(get_day)

but I would convert the date strings to datetime objects first anyway.

Another problem is that you're calling .day which returns a day of month (number 1-31). You probably want to call .date():

def get_day(date_string):
    return datetime.strptime(date_string, '%m/%d/%Y').date()

or directly

df.groupby(lambda x: datetime.strptime(date_string, '%m/%d/%Y').date())