pyarrow.dataset.field

pyarrow.dataset.field(*name_or_index)[source]

Reference a column of the dataset.

Stores only the field’s name. Type and other information is known only when the expression is bound to a dataset having an explicit scheme.

Nested references are allowed by passing multiple names or a tuple of names. For example ('foo', 'bar') references the field named “bar” inside the field named “foo”.

Parameters:
*name_or_indexstr, multiple strings, tuple or int

The name or index of the (possibly nested) field the expression references to.

Returns:
field_exprExpression

Examples

>>> import pyarrow.compute as pc
>>> pc.field("a")
<pyarrow.compute.Expression a>
>>> pc.field(1)
<pyarrow.compute.Expression FieldPath(1)>
>>> pc.field(("a", "b"))
<pyarrow.compute.Expression FieldRef.Nested(FieldRef.Name(a) ...
>>> pc.field("a", "b")
<pyarrow.compute.Expression FieldRef.Nested(FieldRef.Name(a) ...

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