Value

Value(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.
fill_null	Replace any null values with the indicated fill value.
fillna	Deprecated - use fill_null instead.
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(nulls_first=False)

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

Name	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

Name	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()

/tmp/ipykernel_30155/2271248134.py:1: FutureWarning: `Value.case` is deprecated as of v10.0.0; use value.cases() or ibis.cases()
  x.case().when("male", "M").when("female", "F").else_("U").end()

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

Cases not given result in the ELSE case

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

/tmp/ipykernel_30155/2674247010.py:1: FutureWarning: `Value.case` is deprecated as of v10.0.0; use value.cases() or ibis.cases()
  x.case().when("male", "M").else_("OTHER").end()

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

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

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

/tmp/ipykernel_30155/1790570072.py:1: FutureWarning: `Value.case` is deprecated as of v10.0.0; use value.cases() or ibis.cases()
  x.case().when("male", "M").end()

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ SimpleCase(sex, ('male',), ('M',), 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

Name	Type	Description
	Value	Value expression

See Also

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

Examples

>>> import xorq.api as xo
>>> xo.options.interactive = True
>>> t = xo.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

Name	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("int8")

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ Cast(bill_depth_mm, int8) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ int8                      │
├───────────────────────────┤
│                        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")  

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

Name	Type	Description
	Value	Coalesced expression

See Also

ibis.coalesce() Value.fill_null()

Examples

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

┌───┐
│ 4 │
└───┘

collect

collect(where=None, order_by=None, include_null=False)

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	An optional filter expression. If provided, only rows where where is True will be included in the aggregate.	None
order_by	Any	An ordering key (or keys) to use to order the rows before aggregating. If not provided, the order of the items in the result is undefined and backend specific.	None
include_null	bool	Whether to include null values when performing this aggregation. Set to True to include nulls in the result.	False

Returns

Name	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(nulls_first=False)

Sort an expression descending.

fill_null

fill_null(fill_value)

Replace any null values with the indicated fill value.

Parameters

Name	Type	Description	Default
fill_value	Scalar	Value with which to replace NULL 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.fill_null("unrecorded").name("sex")

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

Returns

Name	Type	Description
	Value	self filled with fill_value where it is NULL

fillna

fillna(fill_value)

Deprecated - use fill_null instead.

group_concat

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

Concatenate values using the indicated separator to produce a string.

Parameters

Name	Type	Description	Default
sep	str	The separator to use to join strings.	','
where	ir.BooleanValue | None	An optional filter expression. If provided, only rows where where is True will be included in the aggregate.	None
order_by	Any	An ordering key (or keys) to use to order the rows before aggregating. If not provided, the order of the items in the result is undefined and backend specific.	None

Returns

Name	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.

NoteThe hashing function used is backend-dependent.

Returns

Name	Type	Description
	IntegerValue	The hash value of self

Examples

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

┌─────────────────────┐
│ 8628213525773890682 │
└─────────────────────┘

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

Name	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

Name	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, (1, 2)) ┃
┡━━━━━━━━━━━━━━━━━━━━━┩
│ 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, (1, None)) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━┩
│ boolean                │
├────────────────────────┤
│ True                   │
│ NULL                   │
└────────────────────────┘

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

┏━━━━━━━━━━━━━━━━━━━┓
┃ InValues(x, (1,)) ┃
┡━━━━━━━━━━━━━━━━━━━┩
│ boolean           │
├───────────────────┤
│ True              │
│ NULL              │
│ False             │
└───────────────────┘

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

┏━━━━━━━━━━━━━━━━━━━┓
┃ InValues(x, (3,)) ┃
┡━━━━━━━━━━━━━━━━━━━┩
│ 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

Name	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

Name	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, (18.7, 18.1))) ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ 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

Name	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

Name	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

Name	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

Name	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

Name	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())

'DECIMAL(2,1)'

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

'real'