GroupedTable

GroupedTable(**kwargs)

An intermediate table expression to hold grouping information.

Methods

Name	Description
aggregate	Compute aggregates over a group by.
count	Computing the number of rows per group.
having	Add a post-aggregation result filter expr.
mutate	Return a table projection with window functions applied.
order_by	Sort a grouped table expression by expr.
over	Apply a window over the input expressions.
select	Project new columns out of the grouped table.

aggregate

aggregate(*metrics, **kwds)

Compute aggregates over a group by.

count

count()

Computing the number of rows per group.

Returns

Name	Type	Description
	Table	The aggregated table

having

having(*predicates)

Add a post-aggregation result filter expr.

Expressions like x is None return bool and will not generate a SQL comparison to NULL

Parameters

Name	Type	Description	Default
predicates	ir.BooleanScalar	Expressions that filters based on an aggregate value.	()

Returns

Name	Type	Description
	GroupedTable	A grouped table expression

mutate

mutate(*exprs, **kwexprs)

Return a table projection with window functions applied.

Any arguments can be functions.

Parameters

Name	Type	Description	Default
exprs	ir.Value | Sequence[ir.Value]	List of expressions	()
kwexprs	ir.Value	Expressions	{}

Examples

>>> import ibis
>>> import ibis.selectors as s
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t

┏━━━━━━━━━┳━━━━━━━━━━━┳━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━┳━━━━━━━┓
┃ species ┃ island    ┃ bill_length_mm ┃ bill_depth_mm ┃ flipper_length_mm ┃ body_mass_g ┃ sex    ┃ year  ┃
┡━━━━━━━━━╇━━━━━━━━━━━╇━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━╇━━━━━━━┩
│ string  │ string    │ float64        │ float64       │ int64             │ int64       │ string │ int64 │
├─────────┼───────────┼────────────────┼───────────────┼───────────────────┼─────────────┼────────┼───────┤
│ Adelie  │ Torgersen │           39.1 │          18.7 │               181 │        3750 │ male   │  2007 │
│ Adelie  │ Torgersen │           39.5 │          17.4 │               186 │        3800 │ female │  2007 │
│ Adelie  │ Torgersen │           40.3 │          18.0 │               195 │        3250 │ female │  2007 │
│ Adelie  │ Torgersen │           NULL │          NULL │              NULL │        NULL │ NULL   │  2007 │
│ Adelie  │ Torgersen │           36.7 │          19.3 │               193 │        3450 │ female │  2007 │
│ Adelie  │ Torgersen │           39.3 │          20.6 │               190 │        3650 │ male   │  2007 │
│ Adelie  │ Torgersen │           38.9 │          17.8 │               181 │        3625 │ female │  2007 │
│ Adelie  │ Torgersen │           39.2 │          19.6 │               195 │        4675 │ male   │  2007 │
│ Adelie  │ Torgersen │           34.1 │          18.1 │               193 │        3475 │ NULL   │  2007 │
│ Adelie  │ Torgersen │           42.0 │          20.2 │               190 │        4250 │ NULL   │  2007 │
│ …       │ …         │              … │             … │                 … │           … │ …      │     … │
└─────────┴───────────┴────────────────┴───────────────┴───────────────────┴─────────────┴────────┴───────┘

>>> (
...     t.select("species", "bill_length_mm")
...     .group_by("species")
...     .mutate(centered_bill_len=ibis._.bill_length_mm - ibis._.bill_length_mm.mean())
...     .order_by(s.all())
... )

┏━━━━━━━━━┳━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━┓
┃ species ┃ bill_length_mm ┃ centered_bill_len ┃
┡━━━━━━━━━╇━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━┩
│ string  │ float64        │ float64           │
├─────────┼────────────────┼───────────────────┤
│ Adelie  │           32.1 │         -6.691391 │
│ Adelie  │           33.1 │         -5.691391 │
│ Adelie  │           33.5 │         -5.291391 │
│ Adelie  │           34.0 │         -4.791391 │
│ Adelie  │           34.1 │         -4.691391 │
│ Adelie  │           34.4 │         -4.391391 │
│ Adelie  │           34.5 │         -4.291391 │
│ Adelie  │           34.6 │         -4.191391 │
│ Adelie  │           34.6 │         -4.191391 │
│ Adelie  │           35.0 │         -3.791391 │
│ …       │              … │                 … │
└─────────┴────────────────┴───────────────────┘

Returns

Name	Type	Description
	Table	A table expression with window functions applied

order_by

order_by(*by)

Sort a grouped table expression by expr.

Notes

This API call is ignored in aggregations.

Parameters

Name	Type	Description	Default
by	ir.Value	Expressions to order the results by	()

Returns

Name	Type	Description
	GroupedTable	A sorted grouped GroupedTable

over

over(window=None, *, rows=None, range=None, group_by=None, order_by=None)

Apply a window over the input expressions.

Parameters

Name	Type	Description	Default
window		Window to add to the input	None
rows		Whether to use the ROWS window clause	None
range		Whether to use the RANGE window clause	None
group_by		Grouping key	None
order_by		Ordering key	None

Returns

Name	Type	Description
	GroupedTable	A new grouped table expression

select

select(*exprs, **kwexprs)

Project new columns out of the grouped table.

See Also

GroupedTable.mutate