Generic expressions

Scalars and columns of any element type.

Value

Value(self, arg)

Base class for a data generating expression having a known type.

Methods

Name	Description
asc	Sort an expression ascending.
between	Check if this expression is between lower and upper, inclusive.
case	Create a SimpleCaseBuilder to chain multiple if-else statements.
cases	Create a case expression in one shot.
cast	Cast expression to indicated data type.
coalesce	Return the first non-null value from args.
collect	Aggregate this expression’s elements into an array.
desc	Sort an expression descending.
fillna	Replace any null values with the indicated fill value.
group_concat	Concatenate values using the indicated separator to produce a string.
hash	Compute an integer hash value.
identical_to	Return whether this expression is identical to other.
isin	Check whether this expression’s values are in values.
isnull	Return whether this expression is NULL.
name	Rename an expression to name.
notin	Check whether this expression’s values are not in values.
notnull	Return whether this expression is not NULL.
nullif	Set values to null if they equal the values null_if_expr.
over	Construct a window expression.
substitute	Replace values given in values with replacement.
to_pandas	Convert a column expression to a pandas Series or scalar object.
try_cast	Try cast expression to indicated data type.
type	Return the DataType of self.
typeof	Return the string name of the datatype of self.

asc

asc()

Sort an expression ascending.

between

between(lower, upper)

Check if this expression is between lower and upper, inclusive.

Parameters

Name	Type	Description	Default
lower	Value	Lower bound, inclusive	required
upper	Value	Upper bound, inclusive	required

Returns

Type	Description
BooleanValue	Expression indicating membership in the provided range

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch().limit(5)
>>> t.bill_length_mm.between(35, 38)

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Between(bill_length_mm, 35, 38) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ boolean                         │
├─────────────────────────────────┤
│ False                           │
│ False                           │
│ False                           │
│ NULL                            │
│ True                            │
└─────────────────────────────────┘

case

case()

Create a SimpleCaseBuilder to chain multiple if-else statements.

Add new search expressions with the .when() method. These must be comparable with this column expression. Conclude by calling .end().

Returns

Type	Description
SimpleCaseBuilder	A case builder

See Also

Value.substitute() ibis.cases() ibis.case()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> x = ibis.examples.penguins.fetch().head(5)["sex"]
>>> x

┏━━━━━━━━┓
┃ sex    ┃
┡━━━━━━━━┩
│ string │
├────────┤
│ male   │
│ female │
│ female │
│ NULL   │
│ female │
└────────┘

>>> x.case().when("male", "M").when("female", "F").else_("U").end()

┏━━━━━━━━━━━━━━━━━━━━━━┓
┃ SimpleCase(sex, 'U') ┃
┡━━━━━━━━━━━━━━━━━━━━━━┩
│ string               │
├──────────────────────┤
│ M                    │
│ F                    │
│ F                    │
│ U                    │
│ F                    │
└──────────────────────┘

Cases not given result in the ELSE case

>>> x.case().when("male", "M").else_("OTHER").end()

┏━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ SimpleCase(sex, 'OTHER') ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ string                   │
├──────────────────────────┤
│ M                        │
│ OTHER                    │
│ OTHER                    │
│ OTHER                    │
│ OTHER                    │
└──────────────────────────┘

If you don’t supply an ELSE, then NULL is used

>>> x.case().when("male", "M").end()

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ SimpleCase(sex, Cast(None, string)) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ string                              │
├─────────────────────────────────────┤
│ M                                   │
│ NULL                                │
│ NULL                                │
│ NULL                                │
│ NULL                                │
└─────────────────────────────────────┘

cases

cases(case_result_pairs, default=None)

Create a case expression in one shot.

Parameters

Name	Type	Description	Default
case_result_pairs	Iterable[tuple[ir.BooleanValue, Value]]	Conditional-result pairs	required
default	Value | None	Value to return if none of the case conditions are true	None

Returns

Type	Description
Value	Value expression

See Also

Value.substitute() ibis.cases() ibis.case()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"values": [1, 2, 1, 2, 3, 2, 4]})
>>> t

┏━━━━━━━━┓
┃ values ┃
┡━━━━━━━━┩
│ int64  │
├────────┤
│      1 │
│      2 │
│      1 │
│      2 │
│      3 │
│      2 │
│      4 │
└────────┘

>>> number_letter_map = ((1, "a"), (2, "b"), (3, "c"))
>>> t.values.cases(number_letter_map, default="unk").name("replace")

┏━━━━━━━━━┓
┃ replace ┃
┡━━━━━━━━━┩
│ string  │
├─────────┤
│ a       │
│ b       │
│ a       │
│ b       │
│ c       │
│ b       │
│ unk     │
└─────────┘

cast

cast(target_type)

Cast expression to indicated data type.

Similar to pandas.Series.astype.

Parameters

Name	Type	Description	Default
target_type	Any	Type to cast to. Anything accepted by ibis.dtype()	required

Returns

Type	Description
Value	Casted expression

See Also

Value.try_cast() ibis.dtype()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> x = ibis.examples.penguins.fetch()["bill_depth_mm"]
>>> x

┏━━━━━━━━━━━━━━━┓
┃ bill_depth_mm ┃
┡━━━━━━━━━━━━━━━┩
│ float64       │
├───────────────┤
│          18.7 │
│          17.4 │
│          18.0 │
│          NULL │
│          19.3 │
│          20.6 │
│          17.8 │
│          19.6 │
│          18.1 │
│          20.2 │
│             … │
└───────────────┘

python’s built-in types can be used

>>> x.cast(int)

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Cast(bill_depth_mm, int64) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ int64                      │
├────────────────────────────┤
│                         19 │
│                         17 │
│                         18 │
│                       NULL │
│                         19 │
│                         21 │
│                         18 │
│                         20 │
│                         18 │
│                         20 │
│                          … │
└────────────────────────────┘

or string names

>>> x.cast("uint16")

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Cast(bill_depth_mm, uint16) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ uint16                      │
├─────────────────────────────┤
│                          19 │
│                          17 │
│                          18 │
│                        NULL │
│                          19 │
│                          21 │
│                          18 │
│                          20 │
│                          18 │
│                          20 │
│                           … │
└─────────────────────────────┘

If you make an illegal cast, you won’t know until the backend actually executes it. Consider .try_cast().

>>> ibis.literal("a string").cast("int64")

ConversionException: Conversion Error: Could not convert string 'a string' to INT64

coalesce

coalesce(*args)

Return the first non-null value from args.

Parameters

Name	Type	Description	Default
args	Value	Arguments from which to choose the first non-null value	()

Returns

Type	Description
Value	Coalesced expression

See Also

ibis.coalesce() Value.fillna()

Examples

>>> import ibis
>>> ibis.coalesce(None, 4, 5).name("x")

4

collect

collect(where=None)

Aggregate this expression’s elements into an array.

This function is called array_agg, list_agg, or list in other systems.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter to apply before aggregation	None

Returns

Type	Description
ArrayScalar	Collected array

Examples

Basic collect usage

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"key": list("aaabb"), "value": [1, 2, 3, 4, 5]})
>>> t

┏━━━━━━━━┳━━━━━━━┓
┃ key    ┃ value ┃
┡━━━━━━━━╇━━━━━━━┩
│ string │ int64 │
├────────┼───────┤
│ a      │     1 │
│ a      │     2 │
│ a      │     3 │
│ b      │     4 │
│ b      │     5 │
└────────┴───────┘

>>> t.value.collect()

[1, 2, ... +3]

>>> type(t.value.collect())

ibis.expr.types.arrays.ArrayScalar

Collect elements per group

>>> t.group_by("key").agg(v=lambda t: t.value.collect()).order_by("key")

┏━━━━━━━━┳━━━━━━━━━━━━━━━━┓
┃ key    ┃ v              ┃
┡━━━━━━━━╇━━━━━━━━━━━━━━━━┩
│ string │ array<int64>   │
├────────┼────────────────┤
│ a      │ [1, 2, ... +1] │
│ b      │ [4, 5]         │
└────────┴────────────────┘

Collect elements per group using a filter

>>> t.group_by("key").agg(v=lambda t: t.value.collect(where=t.value > 1)).order_by("key")

┏━━━━━━━━┳━━━━━━━━━━━━━━┓
┃ key    ┃ v            ┃
┡━━━━━━━━╇━━━━━━━━━━━━━━┩
│ string │ array<int64> │
├────────┼──────────────┤
│ a      │ [2, 3]       │
│ b      │ [4, 5]       │
└────────┴──────────────┘

desc

desc()

Sort an expression descending.

fillna

fillna(fill_value)

Replace any null values with the indicated fill value.

Parameters

Name	Type	Description	Default
fill_value	Scalar	Value with which to replace NA values in self	required

See Also

Value.coalesce() ibis.coalesce()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch().limit(5)
>>> t.sex

┏━━━━━━━━┓
┃ sex    ┃
┡━━━━━━━━┩
│ string │
├────────┤
│ male   │
│ female │
│ female │
│ NULL   │
│ female │
└────────┘

>>> t.sex.fillna("unrecorded").name("sex")

┏━━━━━━━━━━━━┓
┃ sex        ┃
┡━━━━━━━━━━━━┩
│ string     │
├────────────┤
│ male       │
│ female     │
│ female     │
│ unrecorded │
│ female     │
└────────────┘

Returns

Type	Description
Value	self filled with fill_value where it is NA

group_concat

group_concat(sep=',', where=None)

Concatenate values using the indicated separator to produce a string.

Parameters

Name	Type	Description	Default
sep	str	Separator will be used to join strings	','
where	ir.BooleanValue | None	Filter expression	None

Returns

Type	Description
StringScalar	Concatenated string expression

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch().limit(5)
>>> t[["bill_length_mm", "bill_depth_mm"]]

┏━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┓
┃ bill_length_mm ┃ bill_depth_mm ┃
┡━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━┩
│ float64        │ float64       │
├────────────────┼───────────────┤
│           39.1 │          18.7 │
│           39.5 │          17.4 │
│           40.3 │          18.0 │
│           NULL │          NULL │
│           36.7 │          19.3 │
└────────────────┴───────────────┘

>>> t.bill_length_mm.group_concat()

'39.1,39.5,40.3,36.7'

>>> t.bill_length_mm.group_concat(sep=": ")

'39.1: 39.5: 40.3: 36.7'

>>> t.bill_length_mm.group_concat(sep=": ", where=t.bill_depth_mm > 18)

'39.1: 36.7'

hash

hash()

Compute an integer hash value.

The hashing function used is backend-dependent.

Returns

Type	Description
IntegerValue	The hash value of self

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> ibis.literal("hello").hash()

-4155090522938856779

identical_to

identical_to(other)

Return whether this expression is identical to other.

Corresponds to IS NOT DISTINCT FROM in SQL.

Parameters

Name	Type	Description	Default
other	Value	Expression to compare to	required

Returns

Type	Description
BooleanValue	Whether this expression is not distinct from other

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> one = ibis.literal(1)
>>> two = ibis.literal(2)
>>> two.identical_to(one + one)

True

isin

isin(values)

Check whether this expression’s values are in values.

NULL values are propagated in the output. See examples for details.

Parameters

Name	Type	Description	Default
values	Value | Sequence[Value]	Values or expression to check for membership	required

Returns

Type	Description
BooleanValue	Expression indicating membership

See Also

Value.notin()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"a": [1, 2, 3], "b": [2, 3, 4]})
>>> t

┏━━━━━━━┳━━━━━━━┓
┃ a     ┃ b     ┃
┡━━━━━━━╇━━━━━━━┩
│ int64 │ int64 │
├───────┼───────┤
│     1 │     2 │
│     2 │     3 │
│     3 │     4 │
└───────┴───────┘

Check against a literal sequence of values

>>> t.a.isin([1, 2])

┏━━━━━━━━━━━━━┓
┃ InValues(a) ┃
┡━━━━━━━━━━━━━┩
│ boolean     │
├─────────────┤
│ True        │
│ True        │
│ False       │
└─────────────┘

Check against a derived expression

>>> t.a.isin(t.b + 1)

┏━━━━━━━━━━━━━━━┓
┃ InSubquery(a) ┃
┡━━━━━━━━━━━━━━━┩
│ boolean       │
├───────────────┤
│ False         │
│ False         │
│ True          │
└───────────────┘

Check against a column from a different table

>>> t2 = ibis.memtable({"x": [99, 2, 99]})
>>> t.a.isin(t2.x)

┏━━━━━━━━━━━━━━━┓
┃ InSubquery(a) ┃
┡━━━━━━━━━━━━━━━┩
│ boolean       │
├───────────────┤
│ False         │
│ True          │
│ False         │
└───────────────┘

NULL behavior

>>> t = ibis.memtable({"x": [1, 2]})
>>> t.x.isin([1, None])

┏━━━━━━━━━━━━━┓
┃ InValues(x) ┃
┡━━━━━━━━━━━━━┩
│ boolean     │
├─────────────┤
│ True        │
│ NULL        │
└─────────────┘

>>> t = ibis.memtable({"x": [1, None, 2]})
>>> t.x.isin([1])

┏━━━━━━━━━━━━━┓
┃ InValues(x) ┃
┡━━━━━━━━━━━━━┩
│ boolean     │
├─────────────┤
│ True        │
│ NULL        │
│ False       │
└─────────────┘

>>> t.x.isin([3])

┏━━━━━━━━━━━━━┓
┃ InValues(x) ┃
┡━━━━━━━━━━━━━┩
│ boolean     │
├─────────────┤
│ False       │
│ NULL        │
│ False       │
└─────────────┘

isnull

isnull()

Return whether this expression is NULL.

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch().limit(5)
>>> t.bill_depth_mm

┏━━━━━━━━━━━━━━━┓
┃ bill_depth_mm ┃
┡━━━━━━━━━━━━━━━┩
│ float64       │
├───────────────┤
│          18.7 │
│          17.4 │
│          18.0 │
│          NULL │
│          19.3 │
└───────────────┘

>>> t.bill_depth_mm.isnull()

┏━━━━━━━━━━━━━━━━━━━━━━━┓
┃ IsNull(bill_depth_mm) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━┩
│ boolean               │
├───────────────────────┤
│ False                 │
│ False                 │
│ False                 │
│ True                  │
│ False                 │
└───────────────────────┘

name

name(name)

Rename an expression to name.

Parameters

Name	Type	Description	Default
name		The new name of the expression	required

Returns

Type	Description
Value	self with name name

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"a": [1, 2]}, name="t")
>>> t.a

┏━━━━━━━┓
┃ a     ┃
┡━━━━━━━┩
│ int64 │
├───────┤
│     1 │
│     2 │
└───────┘

>>> t.a.name("b")

┏━━━━━━━┓
┃ b     ┃
┡━━━━━━━┩
│ int64 │
├───────┤
│     1 │
│     2 │
└───────┘

notin

notin(values)

Check whether this expression’s values are not in values.

Opposite of Value.isin().

Parameters

Name	Type	Description	Default
values	Value | Sequence[Value]	Values or expression to check for lack of membership	required

Returns

Type	Description
BooleanValue	Whether self’s values are not contained in values

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch().limit(5)
>>> t.bill_depth_mm

┏━━━━━━━━━━━━━━━┓
┃ bill_depth_mm ┃
┡━━━━━━━━━━━━━━━┩
│ float64       │
├───────────────┤
│          18.7 │
│          17.4 │
│          18.0 │
│          NULL │
│          19.3 │
└───────────────┘

>>> t.bill_depth_mm.notin([18.7, 18.1])

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Not(InValues(bill_depth_mm)) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ boolean                      │
├──────────────────────────────┤
│ False                        │
│ True                         │
│ True                         │
│ NULL                         │
│ True                         │
└──────────────────────────────┘

notnull

notnull()

Return whether this expression is not NULL.

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch().limit(5)
>>> t.bill_depth_mm

┏━━━━━━━━━━━━━━━┓
┃ bill_depth_mm ┃
┡━━━━━━━━━━━━━━━┩
│ float64       │
├───────────────┤
│          18.7 │
│          17.4 │
│          18.0 │
│          NULL │
│          19.3 │
└───────────────┘

>>> t.bill_depth_mm.notnull()

┏━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ NotNull(bill_depth_mm) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━┩
│ boolean                │
├────────────────────────┤
│ True                   │
│ True                   │
│ True                   │
│ False                  │
│ True                   │
└────────────────────────┘

nullif

nullif(null_if_expr)

Set values to null if they equal the values null_if_expr.

Commonly used to avoid divide-by-zero problems by replacing zero with NULL in the divisor.

Equivalent to (self == null_if_expr).ifelse(ibis.null(), self).

Parameters

Name	Type	Description	Default
null_if_expr	Value	Expression indicating what values should be NULL	required

Returns

Type	Description
Value	Value expression

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> vals = ibis.examples.penguins.fetch().head(5).sex
>>> vals

┏━━━━━━━━┓
┃ sex    ┃
┡━━━━━━━━┩
│ string │
├────────┤
│ male   │
│ female │
│ female │
│ NULL   │
│ female │
└────────┘

>>> vals.nullif("male")

┏━━━━━━━━━━━━━━━━━━━━━┓
┃ NullIf(sex, 'male') ┃
┡━━━━━━━━━━━━━━━━━━━━━┩
│ string              │
├─────────────────────┤
│ NULL                │
│ female              │
│ female              │
│ NULL                │
│ female              │
└─────────────────────┘

over

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

Construct a window expression.

Parameters

Name	Type	Description	Default
window		Window specification	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

Type	Description
Value	A window function expression

substitute

substitute(value, replacement=None, else_=None)

Replace values given in values with replacement.

This is similar to the pandas replace method.

Parameters

Name	Type	Description	Default
value	Value | dict	Expression or dict.	required
replacement	Value | None	If an expression is passed to value, this must be passed.	None
else_	Value | None	If an original value does not match value, then else_ is used. The default of None means leave the original value unchanged.	None

Returns

Type	Description
Value	Replaced values

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.island.value_counts().order_by("island")

┏━━━━━━━━━━━┳━━━━━━━━━━━━━━┓
┃ island    ┃ island_count ┃
┡━━━━━━━━━━━╇━━━━━━━━━━━━━━┩
│ string    │ int64        │
├───────────┼──────────────┤
│ Biscoe    │          168 │
│ Dream     │          124 │
│ Torgersen │           52 │
└───────────┴──────────────┘

>>> t.island.substitute({"Torgersen": "torg", "Biscoe": "bisc"}).name(
...     "island"
... ).value_counts().order_by("island")

┏━━━━━━━━┳━━━━━━━━━━━━━━┓
┃ island ┃ island_count ┃
┡━━━━━━━━╇━━━━━━━━━━━━━━┩
│ string │ int64        │
├────────┼──────────────┤
│ Dream  │          124 │
│ bisc   │          168 │
│ torg   │           52 │
└────────┴──────────────┘

to_pandas

to_pandas(**kwargs)

Convert a column expression to a pandas Series or scalar object.

Parameters

Name	Type	Description	Default
kwargs		Same as keyword arguments to execute	{}

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch().limit(5)
>>> t.to_pandas()

	species	island	bill_length_mm	bill_depth_mm	flipper_length_mm	body_mass_g	sex	year
0	Adelie	Torgersen	39.1	18.7	181.0	3750.0	male	2007
1	Adelie	Torgersen	39.5	17.4	186.0	3800.0	female	2007
2	Adelie	Torgersen	40.3	18.0	195.0	3250.0	female	2007
3	Adelie	Torgersen	NaN	NaN	NaN	NaN	None	2007
4	Adelie	Torgersen	36.7	19.3	193.0	3450.0	female	2007

try_cast

try_cast(target_type)

Try cast expression to indicated data type.

If the cast fails for a row, the value is returned as null or NaN depending on target_type and backend behavior.

Parameters

Name	Type	Description	Default
target_type	Any	Type to try cast to. Anything accepted by ibis.dtype()	required

Returns

Type	Description
Value	Casted expression

See Also

Value.cast() ibis.dtype()

Examples

>>> import ibis
>>> from ibis import _
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"numbers": [1, 2, 3, 4], "strings": ["1.0", "2", "hello", "world"]})
>>> t

┏━━━━━━━━━┳━━━━━━━━━┓
┃ numbers ┃ strings ┃
┡━━━━━━━━━╇━━━━━━━━━┩
│ int64   │ string  │
├─────────┼─────────┤
│       1 │ 1.0     │
│       2 │ 2       │
│       3 │ hello   │
│       4 │ world   │
└─────────┴─────────┘

>>> t = t.mutate(numbers_to_strings=_.numbers.try_cast("string"))
>>> t = t.mutate(strings_to_numbers=_.strings.try_cast("int"))
>>> t

┏━━━━━━━━━┳━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━┓
┃ numbers ┃ strings ┃ numbers_to_strings ┃ strings_to_numbers ┃
┡━━━━━━━━━╇━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━┩
│ int64   │ string  │ string             │ int64              │
├─────────┼─────────┼────────────────────┼────────────────────┤
│       1 │ 1.0     │ 1                  │                  1 │
│       2 │ 2       │ 2                  │                  2 │
│       3 │ hello   │ 3                  │               NULL │
│       4 │ world   │ 4                  │               NULL │
└─────────┴─────────┴────────────────────┴────────────────────┘

type

type()

Return the DataType of self.

typeof

typeof()

Return the string name of the datatype of self.

The values of the returned strings are necessarily backend dependent. e.g. duckdb may say “DOUBLE”, while sqlite may say “real”.

Returns

Type	Description
StringValue	A string indicating the type of the value

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> vals = ibis.examples.penguins.fetch().head(5).bill_length_mm
>>> vals

┏━━━━━━━━━━━━━━━━┓
┃ bill_length_mm ┃
┡━━━━━━━━━━━━━━━━┩
│ float64        │
├────────────────┤
│           39.1 │
│           39.5 │
│           40.3 │
│           NULL │
│           36.7 │
└────────────────┘

>>> vals.typeof()

┏━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ TypeOf(bill_length_mm) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━┩
│ string                 │
├────────────────────────┤
│ DOUBLE                 │
│ DOUBLE                 │
│ DOUBLE                 │
│ DOUBLE                 │
│ DOUBLE                 │
└────────────────────────┘

Different backends have different names for their native types

>>> ibis.duckdb.connect().execute(ibis.literal(5.4).typeof())

'DOUBLE'

>>> ibis.sqlite.connect().execute(ibis.literal(5.4).typeof())

'real'

Column

Column(self, arg)

Methods

Name	Description
approx_median	Return an approximate of the median of self.
approx_nunique	Return the approximate number of distinct elements in self.
arbitrary	Select an arbitrary value in a column.
argmax	Return the value of self that maximizes key.
argmin	Return the value of self that minimizes key.
as_scalar	Inform ibis that the expression should be treated as a scalar.
as_table	Promote the expression to a Table.
count	Compute the number of rows in an expression.
cume_dist	Return the cumulative distribution over a window.
cummax	Return the cumulative max over a window.
cummin	Return the cumulative min over a window.
dense_rank	Position of first element within each group of equal values.
first	Return the first value of a column.
lag	Return the row located at offset rows before the current row.
last	Return the last value of a column.
lead	Return the row located at offset rows after the current row.
max	Return the maximum of a column.
median	Return the median of the column.
min	Return the minimum of a column.
mode	Return the mode of a column.
nth	Return the nth value (0-indexed) over a window.
ntile	Return the integer number of a partitioning of the column values.
nunique	Compute the number of distinct rows in an expression.
percent_rank	Return the relative rank of the values in the column.
preview	Print a subset as a single-column Rich Table.
quantile	Return value at the given quantile.
rank	Compute position of first element within each equal-value group in sorted order.
topk	Return a “top k” expression.
value_counts	Compute a frequency table.

approx_median

approx_median(where=None)

Return an approximate of the median of self.

The result may or may not be exact

Whether the result is an approximation depends on the backend.

Do not depend on the results being exact

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter in values when where is True	None

Returns

Type	Description
Scalar	An approximation of the median of self

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.body_mass_g.approx_median()

4030

>>> t.body_mass_g.approx_median(where=t.species == "Chinstrap")

3700

approx_nunique

approx_nunique(where=None)

Return the approximate number of distinct elements in self.

The result may or may not be exact

Whether the result is an approximation depends on the backend.

Do not depend on the results being exact

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter in values when where is True	None

Returns

Type	Description
Scalar	An approximate count of the distinct elements of self

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.body_mass_g.approx_nunique()

94

>>> t.body_mass_g.approx_nunique(where=t.species == "Adelie")

55

arbitrary

arbitrary(where=None, how=None)

Select an arbitrary value in a column.

Returns an arbitrary (nondeterministic, backend-specific) value from the column. The value will be non-NULL, except if the column is empty or all values are NULL.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	A filter expression	None
how	Any	DEPRECATED	None

Returns

Type	Description
Scalar	An expression

argmax

argmax(key, where=None)

Return the value of self that maximizes key.

Parameters

Name	Type	Description	Default
key	ir.Value	Key to use for max computation.	required
where	ir.BooleanValue | None	Keep values when where is True	None

Returns

Type	Description
Scalar	The value of self that maximizes key

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.species.argmax(t.body_mass_g)

'Gentoo'

>>> t.species.argmax(t.body_mass_g, where=t.island == "Dream")

'Chinstrap'

argmin

argmin(key, where=None)

Return the value of self that minimizes key.

Parameters

Name	Type	Description	Default
key	ir.Value	Key to use for min computation.	required
where	ir.BooleanValue | None	Keep values when where is True	None

Returns

Type	Description
Scalar	The value of self that minimizes key

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.species.argmin(t.body_mass_g)

'Chinstrap'

>>> t.species.argmin(t.body_mass_g, where=t.island == "Biscoe")

'Adelie'

as_scalar

as_scalar()

Inform ibis that the expression should be treated as a scalar.

Creates a scalar subquery from the column expression. Since ibis cannot be sure that the column expression contains only one value, the column expression is wrapped in a scalar subquery and treated as a scalar.

Note that the execution of the scalar subquery will fail if the column expression contains more than one value.

Returns

Type	Description
Scalar	A scalar subquery

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> heavy_gentoo = t.filter(t.species == "Gentoo", t.body_mass_g > 6200)
>>> from_that_island = t.filter(t.island == heavy_gentoo.island.as_scalar())
>>> from_that_island.species.value_counts().order_by("species")

┏━━━━━━━━━┳━━━━━━━━━━━━━━━┓
┃ species ┃ species_count ┃
┡━━━━━━━━━╇━━━━━━━━━━━━━━━┩
│ string  │ int64         │
├─────────┼───────────────┤
│ Adelie  │            44 │
│ Gentoo  │           124 │
└─────────┴───────────────┘

as_table

as_table()

Promote the expression to a Table.

Returns

Type	Description
Table	A table expression

Examples

>>> import ibis
>>> t = ibis.table(dict(a="str"), name="t")
>>> expr = t.a.length().name("len").as_table()
>>> expected = t.select(len=t.a.length())
>>> expr.equals(expected)

True

count

count(where=None)

Compute the number of rows in an expression.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter expression	None

Returns

Type	Description
IntegerScalar	Number of elements in an expression

cume_dist

cume_dist()

Return the cumulative distribution over a window.

cummax

cummax(where=None, group_by=None, order_by=None)

Return the cumulative max over a window.

cummin

cummin(where=None, group_by=None, order_by=None)

Return the cumulative min over a window.

dense_rank

dense_rank()

Position of first element within each group of equal values.

Values are returned in sorted order and duplicate values are ignored.

Equivalent to SQL’s DENSE_RANK().

Returns

Type	Description
IntegerColumn	The rank

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"values": [1, 2, 1, 2, 3, 2]})
>>> t.mutate(rank=t.values.dense_rank())

┏━━━━━━━━┳━━━━━━━┓
┃ values ┃ rank  ┃
┡━━━━━━━━╇━━━━━━━┩
│ int64  │ int64 │
├────────┼───────┤
│      1 │     0 │
│      1 │     0 │
│      2 │     1 │
│      2 │     1 │
│      2 │     1 │
│      3 │     2 │
└────────┴───────┘

first

first(where=None)

Return the first value of a column.

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"chars": ["a", "b", "c", "d"]})
>>> t

┏━━━━━━━━┓
┃ chars  ┃
┡━━━━━━━━┩
│ string │
├────────┤
│ a      │
│ b      │
│ c      │
│ d      │
└────────┘

>>> t.chars.first()

'a'

>>> t.chars.first(where=t.chars != "a")

'b'

lag

lag(offset=None, default=None)

Return the row located at offset rows before the current row.

Parameters

Name	Type	Description	Default
offset	int | ir.IntegerValue | None	Index of row to select	None
default	Value | None	Value used if no row exists at offset	None

last

last(where=None)

Return the last value of a column.

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"chars": ["a", "b", "c", "d"]})
>>> t

┏━━━━━━━━┓
┃ chars  ┃
┡━━━━━━━━┩
│ string │
├────────┤
│ a      │
│ b      │
│ c      │
│ d      │
└────────┘

>>> t.chars.last()

'd'

>>> t.chars.last(where=t.chars != "d")

'c'

lead

lead(offset=None, default=None)

Return the row located at offset rows after the current row.

Parameters

Name	Type	Description	Default
offset	int | ir.IntegerValue | None	Index of row to select	None
default	Value | None	Value used if no row exists at offset	None

max

max(where=None)

Return the maximum of a column.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter in values when where is True	None

Returns

Type	Description
Scalar	The maximum value in self

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.body_mass_g.max()

6300

>>> t.body_mass_g.max(where=t.species == "Chinstrap")

4800

median

median(where=None)

Return the median of the column.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Optional boolean expression. If given, only the values where where evaluates to true will be considered for the median.	None

Returns

Type	Description
Scalar	Median of the column

Examples

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

Compute the median of bill_depth_mm

>>> t.bill_depth_mm.median()

17.3

>>> t.group_by(t.species).agg(median_bill_depth=t.bill_depth_mm.median()).order_by(
...     ibis.desc("median_bill_depth")
... )

┏━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━┓
┃ species   ┃ median_bill_depth ┃
┡━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━┩
│ string    │ float64           │
├───────────┼───────────────────┤
│ Chinstrap │             18.45 │
│ Adelie    │             18.40 │
│ Gentoo    │             15.00 │
└───────────┴───────────────────┘

In addition to numeric types, any orderable non-numeric types such as strings and dates work with median.

>>> t.group_by(t.island).agg(median_species=t.species.median()).order_by(
...     ibis.desc("median_species")
... )

┏━━━━━━━━━━━┳━━━━━━━━━━━━━━━━┓
┃ island    ┃ median_species ┃
┡━━━━━━━━━━━╇━━━━━━━━━━━━━━━━┩
│ string    │ string         │
├───────────┼────────────────┤
│ Biscoe    │ Gentoo         │
│ Dream     │ Chinstrap      │
│ Torgersen │ Adelie         │
└───────────┴────────────────┘

min

min(where=None)

Return the minimum of a column.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter in values when where is True	None

Returns

Type	Description
Scalar	The minimum value in self

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.body_mass_g.min()

2700

>>> t.body_mass_g.min(where=t.species == "Adelie")

2850

mode

mode(where=None)

Return the mode of a column.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter in values when where is True	None

Returns

Type	Description
Scalar	The mode of self

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.body_mass_g.mode()

3800

>>> t.body_mass_g.mode(where=(t.species == "Gentoo") & (t.sex == "male"))

5550

nth

nth(n)

Return the nth value (0-indexed) over a window.

.nth(0) is equivalent to .first(). Negative will result in NULL. If the value of n is greater than the number of rows in the window, NULL will be returned.

Parameters

Name	Type	Description	Default
n	int | ir.IntegerValue	Desired rank value	required

Returns

Type	Description
Column	The nth value over a window

ntile

ntile(buckets)

Return the integer number of a partitioning of the column values.

Parameters

Name	Type	Description	Default
buckets	int | ir.IntegerValue	Number of buckets to partition into	required

nunique

nunique(where=None)

Compute the number of distinct rows in an expression.

Parameters

Name	Type	Description	Default
where	ir.BooleanValue | None	Filter expression	None

Returns

Type	Description
IntegerScalar	Number of distinct elements in an expression

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t.body_mass_g.nunique()

94

>>> t.body_mass_g.nunique(where=t.species == "Adelie")

55

percent_rank

percent_rank()

Return the relative rank of the values in the column.

preview

preview(max_rows=None, max_length=None, max_string=None, max_depth=None, console_width=None)

Print a subset as a single-column Rich Table.

This is an explicit version of what you get when you inspect this object in interactive mode, except with this version you can pass formatting options. The options are the same as those exposed in ibis.options.interactive.

Parameters

Name	Type	Description	Default
max_rows	int | None	Maximum number of rows to display	None
max_length	int | None	Maximum length for pretty-printed arrays and maps.	None
max_string	int | None	Maximum length for pretty-printed strings.	None
max_depth	int | None	Maximum depth for nested data types.	None
console_width	int | float | None	Width of the console in characters. If not specified, the width will be inferred from the console.	None

Examples

>>> import ibis
>>> t = ibis.examples.penguins.fetch()
>>> t.island.preview(max_rows=3, max_string=5)

┏━━━━━━━━┓
┃ island ┃
┡━━━━━━━━┩
│ stri…  │
├────────┤
│ Torg…  │
│ Torg…  │
│ Torg…  │
│ …      │
└────────┘

quantile

quantile(quantile, where=None)

Return value at the given quantile.

The output of this method is a continuous quantile if the input is numeric, otherwise the output is a discrete quantile.

Parameters

Name	Type	Description	Default
quantile	float | ir.NumericValue | Sequence[ir.NumericValue | float]	0 <= quantile <= 1, or an array of such values indicating the quantile or quantiles to compute	required
where	ir.BooleanValue | None	Boolean filter for input values	None

Returns

Type	Description
Scalar	Quantile of the input

Examples

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

Compute the 99th percentile of bill_depth

>>> t.bill_depth_mm.quantile(0.99)

21.1

>>> t.group_by(t.species).agg(p99_bill_depth=t.bill_depth_mm.quantile(0.99)).order_by(
...     ibis.desc("p99_bill_depth")
... )

┏━━━━━━━━━━━┳━━━━━━━━━━━━━━━━┓
┃ species   ┃ p99_bill_depth ┃
┡━━━━━━━━━━━╇━━━━━━━━━━━━━━━━┩
│ string    │ float64        │
├───────────┼────────────────┤
│ Adelie    │         21.200 │
│ Chinstrap │         20.733 │
│ Gentoo    │         17.256 │
└───────────┴────────────────┘

In addition to numeric types, any orderable non-numeric types such as strings and dates work with quantile.

Let’s compute the 99th percentile of the species column

>>> t.group_by(t.island).agg(p99_species=t.species.quantile(0.99)).order_by(
...     ibis.desc("p99_species")
... )

┏━━━━━━━━━━━┳━━━━━━━━━━━━━┓
┃ island    ┃ p99_species ┃
┡━━━━━━━━━━━╇━━━━━━━━━━━━━┩
│ string    │ string      │
├───────────┼─────────────┤
│ Biscoe    │ Gentoo      │
│ Dream     │ Chinstrap   │
│ Torgersen │ Adelie      │
└───────────┴─────────────┘

rank

rank()

Compute position of first element within each equal-value group in sorted order.

Equivalent to SQL’s RANK() window function.

Returns

Type	Description
Int64Column	The min rank

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"values": [1, 2, 1, 2, 3, 2]})
>>> t.mutate(rank=t.values.rank())

┏━━━━━━━━┳━━━━━━━┓
┃ values ┃ rank  ┃
┡━━━━━━━━╇━━━━━━━┩
│ int64  │ int64 │
├────────┼───────┤
│      1 │     0 │
│      1 │     0 │
│      2 │     2 │
│      2 │     2 │
│      2 │     2 │
│      3 │     5 │
└────────┴───────┘

topk

topk(k, by=None)

Return a “top k” expression.

Parameters

Name	Type	Description	Default
k	int	Return this number of rows	required
by	ir.Value | None	An expression. Defaults to count.	None

Returns

Type	Description
Table	A top-k expression

value_counts

value_counts()

Compute a frequency table.

Returns

Type	Description
Table	Frequency table expression

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"chars": char} for char in "aabcddd")
>>> t

┏━━━━━━━━┓
┃ chars  ┃
┡━━━━━━━━┩
│ string │
├────────┤
│ a      │
│ a      │
│ b      │
│ c      │
│ d      │
│ d      │
│ d      │
└────────┘

>>> t.chars.value_counts().order_by("chars")

┏━━━━━━━━┳━━━━━━━━━━━━━┓
┃ chars  ┃ chars_count ┃
┡━━━━━━━━╇━━━━━━━━━━━━━┩
│ string │ int64       │
├────────┼─────────────┤
│ a      │           2 │
│ b      │           1 │
│ c      │           1 │
│ d      │           3 │
└────────┴─────────────┘

Scalar

Scalar(self, arg)

Methods

Name	Description
as_scalar	Inform ibis that the expression should be treated as a scalar.
as_table	Promote the scalar expression to a table.

as_scalar

as_scalar()

Inform ibis that the expression should be treated as a scalar.

If the expression is a literal, it will be returned as is. If it depends on a table, it will be turned to a scalar subquery.

Returns

Type	Description
Scalar	A scalar subquery or a literal

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> max_gentoo_weight = t.filter(t.species == "Gentoo").body_mass_g.max()
>>> light_penguins = t.filter(t.body_mass_g < max_gentoo_weight / 2)
>>> light_penguins.species.value_counts().order_by("species")

┏━━━━━━━━━━━┳━━━━━━━━━━━━━━━┓
┃ species   ┃ species_count ┃
┡━━━━━━━━━━━╇━━━━━━━━━━━━━━━┩
│ string    │ int64         │
├───────────┼───────────────┤
│ Adelie    │            15 │
│ Chinstrap │             2 │
└───────────┴───────────────┘

as_table

as_table()

Promote the scalar expression to a table.

Returns

Type	Description
Table	A table expression

Examples

Promote an aggregation to a table

>>> import ibis
>>> import ibis.expr.types as ir
>>> t = ibis.table(dict(a="str"), name="t")
>>> expr = t.a.length().sum().name("len").as_table()
>>> isinstance(expr, ir.Table)

True

Promote a literal value to a table

>>> import ibis.expr.types as ir
>>> lit = ibis.literal(1).name("a").as_table()
>>> isinstance(lit, ir.Table)

True

literal

ibis.literal(value, type=None)

Create a scalar expression from a Python value.

Use specific functions for arrays, structs and maps

Ibis supports literal construction of arrays using the following functions:

1. ibis.array
2. ibis.struct
3. ibis.map

Constructing these types using literal will be deprecated in a future release.

Parameters

Name	Type	Description	Default
value	Any	A Python value	required
type	dt.DataType | str | None	An instance of DataType or a string indicating the ibis type of value. This parameter can be used in cases where ibis’s type inference isn’t sufficient for discovering the type of value.	None

Returns

Type	Description
Scalar	An expression representing a literal value

Examples

Construct an integer literal

>>> import ibis
>>> x = ibis.literal(42)
>>> x.type()

Int8(nullable=True)

Construct a float64 literal from an int

>>> y = ibis.literal(42, type="double")
>>> y.type()

Float64(nullable=True)

Ibis checks for invalid types

>>> ibis.literal("foobar", type="int64")  

TypeError: Unable to normalize 'foobar' to Int64(nullable=True)

param

ibis.param(type)

Create a deferred parameter of a given type.

Parameters

Name	Type	Description	Default
type	dt.DataType	The type of the unbound parameter, e.g., double, int64, date, etc.	required

Returns

Type	Description
Scalar	A scalar expression backend by a parameter

Examples

>>> from datetime import date
>>> import ibis
>>> start = ibis.param("date")
>>> t = ibis.memtable(
...     {
...         "date_col": [date(2013, 1, 1), date(2013, 1, 2), date(2013, 1, 3)],
...         "value": [1.0, 2.0, 3.0],
...     },
... )
>>> expr = t.filter(t.date_col >= start).value.sum()
>>> expr.execute(params={start: date(2013, 1, 1)})

6.0

>>> expr.execute(params={start: date(2013, 1, 2)})

5.0

>>> expr.execute(params={start: date(2013, 1, 3)})

3.0

NA

ibis.expr.api.NA

The NULL scalar.

Examples

>>> import ibis
>>> my_null = ibis.NA
>>> my_null.isnull()

True

null

ibis.null()

Create a NULL/NA scalar.

coalesce

ibis.coalesce(*args)

Return the first non-null value from args.

Parameters

Name	Type	Description	Default
args	Any	Arguments from which to choose the first non-null value	()

Returns

Type	Description
Value	Coalesced expression

See Also

Value.coalesce() Value.fillna()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> ibis.coalesce(None, 4, 5)

4

least

ibis.least(*args)

Compute the smallest value among the supplied arguments.

Parameters

Name	Type	Description	Default
args	Any	Arguments to choose from	()

Returns

Type	Description
Value	Minimum of the passed arguments

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> ibis.least(None, 4, 5)

4

greatest

ibis.greatest(*args)

Compute the largest value among the supplied arguments.

Parameters

Name	Type	Description	Default
args	Any	Arguments to choose from	()

Returns

Type	Description
Value	Maximum of the passed arguments

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> ibis.greatest(None, 4, 5)

5

asc

ibis.asc(expr)

Create a ascending sort key from asc or column name.

Parameters

Name	Type	Description	Default
expr	ir.Column | str	The expression or column name to use for sorting	required

See Also

Value.asc()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t[["species", "year"]].order_by(ibis.asc("year")).head()

┏━━━━━━━━━┳━━━━━━━┓
┃ species ┃ year  ┃
┡━━━━━━━━━╇━━━━━━━┩
│ string  │ int64 │
├─────────┼───────┤
│ Adelie  │  2007 │
│ Adelie  │  2007 │
│ Adelie  │  2007 │
│ Adelie  │  2007 │
│ Adelie  │  2007 │
└─────────┴───────┘

Returns

Type	Description
ir.ValueExpr	An expression

desc

ibis.desc(expr)

Create a descending sort key from expr or column name.

Parameters

Name	Type	Description	Default
expr	ir.Column | str	The expression or column name to use for sorting	required

See Also

Value.desc()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.examples.penguins.fetch()
>>> t[["species", "year"]].order_by(ibis.desc("year")).head()

┏━━━━━━━━━┳━━━━━━━┓
┃ species ┃ year  ┃
┡━━━━━━━━━╇━━━━━━━┩
│ string  │ int64 │
├─────────┼───────┤
│ Adelie  │  2009 │
│ Adelie  │  2009 │
│ Adelie  │  2009 │
│ Adelie  │  2009 │
│ Adelie  │  2009 │
└─────────┴───────┘

Returns

Type	Description
ir.ValueExpr	An expression

ifelse

ibis.ifelse(condition, true_expr, false_expr)

Construct a ternary conditional expression.

Parameters

Name	Type	Description	Default
condition	Any	A boolean expression	required
true_expr	Any	Expression to return if condition evaluates to True	required
false_expr	Any	Expression to return if condition evaluates to False or NULL	required

Returns

Type	Description
ir.Value	The value of true_expr if condition is True else false_expr

See Also

BooleanValue.ifelse()

Examples

>>> import ibis
>>> ibis.options.interactive = True
>>> t = ibis.memtable({"condition": [True, False, True, None]})
>>> ibis.ifelse(t.condition, "yes", "no")

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ IfElse(condition, 'yes', 'no') ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ string                         │
├────────────────────────────────┤
│ yes                            │
│ no                             │
│ yes                            │
│ no                             │
└────────────────────────────────┘

case

ibis.case()

Begin constructing a case expression.

Use the .when method on the resulting object followed by .end to create a complete case expression.

Returns

Type	Description
SearchedCaseBuilder	A builder object to use for constructing a case expression.

See Also

Value.case()

Examples

>>> import ibis
>>> from ibis import _
>>> ibis.options.interactive = True
>>> t = ibis.memtable(
...     {
...         "left": [1, 2, 3, 4],
...         "symbol": ["+", "-", "*", "/"],
...         "right": [5, 6, 7, 8],
...     }
... )
>>> t.mutate(
...     result=(
...         ibis.case()
...         .when(_.symbol == "+", _.left + _.right)
...         .when(_.symbol == "-", _.left - _.right)
...         .when(_.symbol == "*", _.left * _.right)
...         .when(_.symbol == "/", _.left / _.right)
...         .end()
...     )
... )

┏━━━━━━━┳━━━━━━━━┳━━━━━━━┳━━━━━━━━━┓
┃ left  ┃ symbol ┃ right ┃ result  ┃
┡━━━━━━━╇━━━━━━━━╇━━━━━━━╇━━━━━━━━━┩
│ int64 │ string │ int64 │ float64 │
├───────┼────────┼───────┼─────────┤
│     1 │ +      │     5 │     6.0 │
│     2 │ -      │     6 │    -4.0 │
│     3 │ *      │     7 │    21.0 │
│     4 │ /      │     8 │     0.5 │
└───────┴────────┴───────┴─────────┘

to_sql

ibis.to_sql(expr, dialect=None, pretty=True, **kwargs)

Return the formatted SQL string for an expression.

Parameters

Name	Type	Description	Default
expr	ir.Expr	Ibis expression.	required
dialect	str | None	SQL dialect to use for compilation.	None
pretty	bool	Whether to use pretty formatting.	True
kwargs		Scalar parameters	{}

Returns

Type	Description
str	Formatted SQL string