python pandas: get fiscal quarter from fiscal year and month (for UK)

Question

I have a dataframe with two useful columns 1) fiscal year, 2) date. I want to add a new column which shows the fiscal quarter.

FYI - UK Financial year runs from 1 April to 31 March

my data looks like:

    fiscal year  date
    FY15/16      2015-11-01
    FY14/15      2014-10-01
    FY15/16      2016-02-01

I want it to look like this:

    fiscal year  date        Quarter
    FY15/16      2015-11-01  q3
    FY14/15      2014-10-01  q3
    FY15/16      2016-02-01  q4

Really hope I got the quarters right!

Code below works but I believe it returns American financial quarters but I want UK.

df['Quater'] = df['Date'].dt.quarter 

Answer 1

import pandas as pd
df = pd.DataFrame({'date': ['2015-11-01', '2014-10-01', '2016-02-01'],
                   'fiscal year': ['FY15/16', 'FY14/15', 'FY15/16']})
df['Quarter'] = pd.PeriodIndex(df['date'], freq='Q-MAR').strftime('Q%q')
print(df)

yields

         date fiscal year Quarter
0  2015-11-01     FY15/16      Q3
1  2014-10-01     FY14/15      Q3
2  2016-02-01     FY15/16      Q4

---

The default quarterly frequency Q is equivalent to Q-DEC.

In [60]: pd.PeriodIndex(df['date'], freq='Q')
Out[60]: PeriodIndex(['2015Q4', '2014Q4', '2016Q1'], dtype='int64', freq='Q-DEC')

Q-DEC specifies quarterly periods whose last quarter ends on the last day in December. Q-MAR specifies quarterly periods whose last quarter ends on the last day in March.

In [86]: pd.PeriodIndex(df['date'], freq='Q-MAR')
Out[86]: PeriodIndex(['2016Q3', '2015Q3', '2016Q4'], dtype='int64', freq='Q-MAR')

Answer 2

If you are working with this format (dd/mm/yyyy), like in the UK for example, the following worked for me:

df['Fiscal UK quarters'] = pd.to_datetime(df['Date'].values.tolist(), dayfirst=True).to_period(freq='Q-MAR')