Cumulative sum and overall percentage over time using multiple groupby + aggs with year and month

Question

I have data with a single column containing a date (Date) and another column with categorical data (A: Yes, No, Unknown).

I'd like to show the total percentage of "Yes" over time, but relative to the point in time of the observation (i.e., number of "Yes" / cumulative sum at that point in time).

Assume I have data like:

df

Date         A
2022-08-22   Unknown
2022-08-23   Yes
2022-08-24   No
2022-08-25   Unknown
2022-09-13   Yes
# . . .

df.info()

<class 'pandas.core.frame.DataFrame'>
RangeIndex: 246 entries, 0 to 245
Data columns (total 2 columns):
 #   Column  Non-Null Count  Dtype         
---  ------  --------------  -----         
 0   Date    246 non-null    datetime64[ns]
 1   A       246 non-null    object        
dtypes: datetime64[ns](1), object(1)

The main question is: Is there a trend showing that A=="Yes" more frequently as time progresses by year/month?

I'd like to show, for each year/month, the percentage of Yes's compared to the total sum of all rows for that year/month. So if there are 10 records in June 2022, and 2 have A=="Yes", then the value for June 2022 is 20%. It might look kind of like this, where the value/A is here the percentage:

Date  Date
2022  1        0.05
      2        0.22
      3        0.88
      4        0.79
      5        0.51
      6        0.04
      7        0.20
      8        0.91
      9        0.98
Name: A, dtype: int64

I can get a count of "Yes" by year and month like so:

df.loc[df["A"] == "Yes"]["A"].groupby([df["Date"].dt.year, df["Date"].dt.month]).agg("count")

But I'm not sure how to get relative percentage per month compared to the cumulative sum per year/month, which requires dividing A=="Yes" into total row count per year/month.

To have sample data:

d = [{'Date': Timestamp('2022-08-02 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-14 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-18 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-01-19 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-20 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-21 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-01-22 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-01-23 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-01-24 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-01-25 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-01-26 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-01-27 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-28 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-29 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-30 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-01-31 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-01 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-02-02 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-03 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-04 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-05 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-02-06 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-02-07 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-20 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-02-21 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-02-22 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-23 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-02-24 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-02-25 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-02-26 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-27 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-02-28 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-01 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-02 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-03 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-04 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-03-05 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-06 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-07 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-03-08 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-09 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-03-10 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-11 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-12 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-03-13 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-14 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-15 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-16 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-03-17 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-18 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-19 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-02 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-14 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-01-18 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-01-19 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-20 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-01-21 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-26 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-03-27 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-28 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-03-29 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-03-30 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-03-31 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-04-01 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-02 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-03 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-04-04 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-05 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-06 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-07 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-08 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-09 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-10 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-11 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-12 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-04-13 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-14 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-15 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-16 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-17 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-18 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-19 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-20 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-21 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-22 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-04-23 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-04-24 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-04-25 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-04-26 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-27 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-28 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-04-29 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-04-30 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-05-01 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-02 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-03 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-04 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-05 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-06 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-07 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-08 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-09 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-10 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-11 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-12 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-13 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-14 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-15 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-16 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-05-17 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-18 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-19 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-20 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-05-21 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-05-22 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-05-23 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-24 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-25 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-26 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-27 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-28 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-05-29 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-30 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-05-31 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-01 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-02 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-06-03 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-06-04 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-05 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-06 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-07 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-08 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-09 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-10 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-11 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-06-12 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-13 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-06-14 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-15 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-16 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-17 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-18 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-19 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-06-20 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-21 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-22 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-23 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-06-24 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-25 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-26 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-27 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-06-28 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-06-29 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-06-30 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-01 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-02 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-03 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-04 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-05 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-06 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-07 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-08 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-09 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-10 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-11 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-12 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-13 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-14 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-15 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-16 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-16 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-16 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-16 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-17 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-28 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-07-29 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-30 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-07-31 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-01 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-02 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-03 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-04 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-05 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-06 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-07 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-08 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-09 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-10 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-11 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-12 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-13 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-14 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-15 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-16 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-17 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-18 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-19 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-20 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-21 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-22 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-23 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-24 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-25 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-08-26 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-27 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-28 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-29 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-08-30 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-08-31 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-01 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-02 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-03 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-04 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-05 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-06 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-07 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-08 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-09 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-10 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-11 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-12 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-13 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-14 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-15 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-16 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-17 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-18 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-19 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-20 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-21 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-22 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-23 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-24 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-25 00:00:00'), 'A': 'Yes'},
 {'Date': Timestamp('2022-09-26 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-27 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-28 00:00:00'), 'A': 'Unknown'},
 {'Date': Timestamp('2022-09-29 00:00:00'), 'A': 'No'},
 {'Date': Timestamp('2022-09-30 00:00:00'), 'A': 'No'}]

df = pd.DataFrame(d)

can you provide an explicit example rather than a description? And the matching expected output — mozway, Dec 09 '22 at 10:54
Don't **describe**, provide an example in the form of a minimal input DataFrame and the matching expected output — mozway, Dec 09 '22 at 21:15
I also included a copy/pastable dataframe instantiation code to have some sample data — Dan, Dec 10 '22 at 16:23

score 2 · Accepted Answer · answered Dec 10 '22 at 16:34

You could try the following:

df_counts = (
    df
    .assign(Year=df["Date"].dt.year, Month=df["Date"].dt.month)
    .pivot_table(index=["Year", "Month"], columns="A", aggfunc="count", fill_value=0)
    .droplevel(0, axis=1)
)
result = df_counts["Yes"].div(df_counts.sum(axis=1))

.pivot_table groups over ["Year", "Month"], counts the occurrences of the values in column A, and then puts them in respective columns.
Then divide the Yes column by the total counts per Year-Month (df_counts.sum(axis=1)).

Result for the sample dataframe:

Year  Month
2022  1        0.277778
      2        0.125000
      3        0.320000
      4        0.233333
      5        0.161290
      6        0.466667
      7        0.387097
      8        0.272727
      9        0.281250
Name: Yes, dtype: float64

Cumulative sum and overall percentage over time using multiple groupby + aggs with year and month

1 Answers1

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