Method: Polars::Functions#head

Defined in:
lib/polars/functions/lazy.rb

#head(column, n = 10) ⇒ Expr

Get the first n rows.

This function is syntactic sugar for col(column).head(n).

Examples:

df = Polars::DataFrame.new(
  {
    "a" => [1, 8, 3],
    "b" => [4, 5, 2],
    "c" => ["foo", "bar", "foo"]
  }
)
df.select(Polars.head("a"))
# =>
# shape: (3, 1)
# ┌─────┐
# │ a   │
# │ --- │
# │ i64 │
# ╞═════╡
# │ 1   │
# │ 8   │
# │ 3   │
# └─────┘
df.select(Polars.head("a", 2))
# =>
# shape: (2, 1)
# ┌─────┐
# │ a   │
# │ --- │
# │ i64 │
# ╞═════╡
# │ 1   │
# │ 8   │
# └─────┘

Parameters:

  • column (Object) —

    Column name.

  • n (Integer) (defaults to: 10) —

    Number of rows to return.

Returns:


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# File 'lib/polars/functions/lazy.rb', line 620

def head(column, n = 10)
  col(column).head(n)
end