python - Pandas: add crosstab totals

Question

How can I add to my crosstab an additional row and an additional column for the totals?

df = pd.DataFrame({"A": np.random.randint(0,2,100), "B" : np.random.randint(0,2,100)})
ct = pd.crosstab(new.A, new.B)
ct

I thought I would add the new column (obtained by summing over the rows) by

ct["Total"] = ct.0 + ct.1

but this does not work.

Answer 1

In fact pandas.crosstab already provides an option margins, which does exactly what you want.

> df = pd.DataFrame({"A": np.random.randint(0,2,100), "B" : np.random.randint(0,2,100)})
> pd.crosstab(df.A, df.B, margins=True)
B     0   1  All
A               
0    26  21   47
1    25  28   53
All  51  49  100

Basically, by setting margins=True, the resulting frequency table will add an "All" column and an "All" row that compute the subtotals.