Calculate Last Friday of Month in Pandas

Question

I\'ve written this function to get the last Thursday of the month

def last_thurs_date(date):
    month=date.dt.month
    year=date.dt.year
    
    cal = cale         


        

Answer 1

Scalar datetime objects don't have a dt accessor, series do: see pd.Series.dt. If you remove this, your function works fine. The key is understanding that pd.Series.apply passes scalars to your custom function via a loop, not an entire series.

def last_thurs_date(date):
    month = date.month
    year = date.year

    cal = calendar.monthcalendar(year, month)
    last_thurs_date = cal[4][4]
    if month < 10:
        thurday_date = str(year)+'-0'+ str(month)+'-' + str(last_thurs_date)
    else:
        thurday_date = str(year) + '-' + str(month) + '-' + str(last_thurs_date)
    return thurday_date

You can rewrite your logic more succinctly via f-strings (Python 3.6+) and a ternary statement:

def last_thurs_date(date):
    month = date.month
    year = date.year
    last_thurs_date = calendar.monthcalendar(year, month)[4][4]
    return f'{year}{"-0" if month < 10 else "-"}{month}-{last_thurs_date}'