Add +1 day to each value in the column

Question

I have a column of dates. They are all the same date. How do I add 1 extra day to every date value in that column?

Here is my code:

aday = dt.timedelta(days=1) 
datetickerdf = pd.read_csv('datesandtickers.csv')
datetickerdf = pd.DataFrame(datetickerdf, columns=["ticker","date"])
datetickerdf['date'] = datetickerdf['date'] + aday
datetickerdf

I get this error: "unsupported operand type(s) for +: 'Timedelta' and 'str'"

How can I transform "aday" into something that can be used for the + operator? I want to add an extra day to all the dates in my column.

Answer 1

You need to convert your string into a date object. Once your string is a date object, you can apply the time delta and then turn the new date object back into a string.

#Assuming datetickerdf['date']  is something like 21 June, 2018
#My Delta
aday = dt.timedelta(days=1) 
#The date in the file converted to a date object
fileday = dt.datetime.strptime(datetickerdf['date'], "%d %B, %Y")
#New date calculated with delta
newday = fileday+aday
#Write it back to a file
datetickerdf['date'] = newday.strftime("%d %B, %Y")

Use this page to get the right format string to parse and rewrite the string https://docs.python.org/3/library/datetime.html#strftime-strptime-behavior

Answer 2

Use pd.Timedelta to create datetimelike one day

datetickerdf['date'] = datetickerdf['date'] + pd.Timedelta(days=1)