[Python] How to create a cross table in Python Polars?

I would like to count unique combinations in two Polars columns.

In R


df <- data.frame(a = c(2,0,1,0,0,0), b = c(1,1,1,0,0,1))
table(df)
0 1
0 2 2
1 0 1
2 0 1

In Pandas


import numpy as np
a = np.array([2,0,1,0,0,0])
b = np.array([1,1,1,0,0,1])
pd.crosstab(a, b)
0 1
0 2 2
1 0 1
2 0 1

In Polars


Is this the proper way?

df = pl.DataFrame(
{
"a": [2,0,1,0,0,0],
"b": [1,1,1,0,0,1]
}
)
df.pivot(on="a", index="b", values="a", aggregate_function="len").fill_null(0)

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