Datatypes

gel-python automatically converts Gel types to the corresponding Python types and vice versa.

The table below shows the correspondence between Gel and Python types.

Gel Type	Python Type
`Set`	`gel.Set`
`array<anytype>`	`gel.Array`
`anytuple`	`gel.Tuple` or `gel.NamedTuple`
`anyenum`	`gel.EnumValue`
`Object`	`gel.Object`
`bool`	`bool`
`bytes`	`bytes`
`str`	`str`
`cal::local_date`	`datetime.date`
`cal::local_time`	offset-naive `datetime.time`
`cal::local_datetime`	offset-naive `datetime.datetime`
`cal::relative_duration`	`gel.RelativeDuration`
`cal::date_duration`	`gel.DateDuration`
`datetime`	offset-aware `datetime.datetime`
`duration`	`datetime.timedelta`
`float32`, `float64`	`float`
`int16`, `int32`, `int64`, `bigint`	`int`
`decimal`	`Decimal`
`json`	`str`
`uuid`	`uuid.UUID`

Inexact single-precision float values may have a different representation when decoded into a Python float. This is inherent to the implementation of limited-precision floating point types. If you need the decimal representation to match, cast the expression to float64 or decimal in your query.

Sets

class

Set

This is list since version 1.0.

Objects

class

Object

An immutable representation of an object instance returned from a query.

gel.Object instances are dataclass-compatible since version 1.0, for example, dataclasses.is_dataclass() will return True, and dataclasses.asdict() will work on gel.Object instances.

gel.Object.__hash__ is just object.__hash__ in version 1.0. Similarly, == is equivalent to the is operator comparing gel.Object instances, and <, <=, >, >= are not allowed on gel.Object instances.

The value of an object property or a link can be accessed through a corresponding attribute:

Copy

>>>

import gel

Copy

>>>

client = gel.create_client()

Copy

>>> 
... 
... 
...

r = client.query_single('''
    SELECT schema::ObjectType {name}
    FILTER .name = 'std::Object'
    LIMIT 1''')

Copy

>>>

Object{name := 'std::Object'}

Copy

>>>

r.name

'std::Object'

interface

obj[linkname]

Return a gel.Link or a gel.LinkSet instance representing the instance(s) of link linkname associated with obj.

Example:

Copy

>>>

import gel

Copy

>>>

client = gel.create_client()

Copy

>>> 
... 
... 
... 
...

r = client.query_single('''
    SELECT schema::Property {name, annotations: {name, @value}}
    FILTER .name = 'listen_port'
           AND .source.name = 'cfg::Config'
    LIMIT 1''')

Copy

>>>

Object {
    name: 'listen_port',
    annotations: {
        Object {
            name: 'cfg::system',
            @value: 'true'
        }
    }
}

Copy

>>>

r['annotations']

LinkSet(name='annotations')

Copy

>>>

l = list(r['annotations])[0]

Copy

>>>

l.value

'true'

Links

class

Link

An immutable representation of an object link.

Links are created when gel.Object is accessed via a [] operator. Using Link objects explicitly is useful for accessing link properties.

class

LinkSet

An immutable representation of a set of Links.

LinkSets are created when a multi link on gel.Object is accessed via a [] operator.

Tuples

class

Tuple

This is tuple since version 1.0.

Named Tuples

class

NamedTuple

An immutable value representing an Gel named tuple value.

gel.NamedTuple is a subclass of tuple and is duck-type compatible with collections.namedtuple since version 1.0.

Instances of gel.NamedTuple generally behave similarly to namedtuple:

Copy

>>>

import gel

Copy

>>>

client = gel.create_client()

Copy

>>>

r = client.query_single('''SELECT (a := 1, b := 'a', c := [3])''')

Copy

>>>

(a := 1, b := 'a', c := [3])

Copy

>>>

r.b

'a'

Copy

>>>

r[0]

Copy

>>>

r == (1, 'a', [3])

True

Copy

>>>

r._fields

('a', 'b', 'c')

Arrays

class

Array

This is list since version 1.0.

RelativeDuration

class

RelativeDuration

An immutable value representing an Gel cal::relative_duration value.

Copy

>>>

import gel

Copy

>>>

client = gel.create_client()

Copy

>>>

r = client.query_single('''SELECT <cal::relative_duration>"1 year 2 days 3 seconds"''')

Copy

>>>

<gel.RelativeDuration "P1Y2DT3S">

Copy

>>>

r.months

Copy

>>>

r.days

Copy

>>>

r.microseconds

DateDuration

class

DateDuration

An immutable value representing an Gel cal::date_duration value.

Copy

>>>

import gel

Copy

>>>

client = gel.create_client()

Copy

>>>

r = client.query_single('''SELECT <cal::date_duration>"1 year 2 days"''')

Copy

>>>

<gel.DateDuration "P1Y2D">

Copy

>>>

r.months

Copy

>>>

r.days

EnumValue

class

EnumValue

An immutable value representing an Gel enum value.

Since version 1.0, gel.EnumValue is a subclass of enum.Enum. Actual enum values are instances of ad-hoc enum classes created by the codecs to represent the actual members defined in your Gel schema.

Copy

>>>

import gel

Copy

>>>

client = gel.create_client()

Copy

>>>

r = client.query_single("""SELECT <Color>'red'""")

Copy

>>>

<gel.EnumValue 'red'>

Copy

>>>

str(r)

'red'

Copy

>>>

r.value  # added in 1.0

'red'

Copy

>>>

r.name  # added in 1.0, simply str.upper() of r.value

'RED'

Datatypes​

Sets​

Objects​

Links​

Tuples​

Named Tuples​

Arrays​

RelativeDuration​

DateDuration​

EnumValue​

Datatypes

Sets

Objects

Links

Tuples

Named Tuples

Arrays

RelativeDuration

DateDuration

EnumValue