pyarrow.dataset.Expression¶

class pyarrow.dataset.Expression¶

Bases: pyarrow.lib._Weakrefable

A logical expression to be evaluated against some input.

To create an expression:

Use the factory function pyarrow.compute.scalar() to create a scalar (not necessary when combined, see example below).
Use the factory function pyarrow.compute.field() to reference a field (column in table).
Compare fields and scalars with <, <=, ==, >=, >.
Combine expressions using python operators & (logical and), | (logical or) and ~ (logical not). Note: python keywords and, or and not cannot be used to combine expressions.
Check whether the expression is contained in a list of values with the pyarrow.compute.Expression.isin() member function.

Examples

>>> import pyarrow.compute as pc
>>> (pc.field("a") < pc.scalar(3)) | (pc.field("b") > 7)
<pyarrow.compute.Expression ((a < 3:int64) or (b > 7:int64))>
>>> ds.field('a') != 3
<pyarrow.compute.Expression (a != 3)>
>>> ds.field('a').isin([1, 2, 3])
<pyarrow.compute.Expression (a is in [
  1,
  2,
  3
])>

__init__(*args, **kwargs)¶

Methods

`__init__`(args, *kwargs)
`cast`(self, type, bool safe=True)	Explicitly change the expression's data type
`equals`(self, Expression other)
`is_null`(self, bool nan_is_null=False)	Checks whether the expression is null
`is_valid`(...)	Checks whether the expression is not-null (valid)
`isin`(self, values)	Checks whether the expression is contained in values

cast(self, type, bool safe=True)¶: Explicitly change the expression’s data type

equals(self, Expression other)¶

is_null(self, bool nan_is_null=False)¶: Checks whether the expression is null

is_valid(self) Checks whether the expression is not-null (valid)¶: Checks whether the expression is not-null (valid)

isin(self, values)¶: Checks whether the expression is contained in values

pyarrow.dataset.Scanner

Plasma In-Memory Object Store