Method: Polars::Expr#n_unique

Defined in:

lib/polars/expr.rb

#n_unique ⇒ Expr

Count unique values.

Examples:

df = Polars::DataFrame.new({"a" => [1, 1, 2]})
df.select(Polars.col("a").n_unique)
# =>
# shape: (1, 1)
# ┌─────┐
# │ a   │
# │ --- │
# │ u32 │
# ╞═════╡
# │ 2   │
# └─────┘

Returns:

• (Expr)

# File 'lib/polars/expr.rb', line 2165

def n_unique
  _from_rbexpr(_rbexpr.n_unique)
end