Characteristics

The galactic.characteristics module defines characteristics.

Characteristic for the superclass of all characteristics
Named for named characteristics
Key for characteristics whose calls to an individual will be retrieved by a key access
Property for characteristics whose calls to an individual will be retrieved by a property access
Item for characteristics whose calls to an individual will be retrieved by a nth access
Slice for characteristics whose calls to an individual will be retrieved by a slice access

class Characteristic(*components: galactic.characteristics.Characteristic, cache: bool = True, label: Optional[str] = None, explanation: Optional[str] = None)

The Characteristic class is the super class of all characteristics.

It is designed for subclassing.

A characteristic can be called on an individual. It returns a data of this individual.

__call__(individual: Any) → Optional[Any]

Make this characteristic callable.

This method should be overridden in sub-classes.

Parameters:: individual (object) – Any python object.
Returns:: The individual characteristic.
Return type:: Optional[Any]

Hint

If the returned value is None, the characteristic is undetermined.

__init__(*components: galactic.characteristics.Characteristic, cache: bool = True, label: Optional[str] = None, explanation: Optional[str] = None) → None

Initialise a Characteristic instance.

Parameters:

*components – Inner characteristics (if any).

Keyword Arguments:

cache (bool) – Is this characteristic is cached?
label (Optional[str]) – An optional label.
explanation (Optional[str]) – An optional explanation in markdown text.

property cache: bool

Get the cache property.

Returns:: The cache property.
Return type:: bool

clear() → None: Clear the cache.

property components: Sequence[galactic.characteristics.Characteristic]

Get the inner characteristics.

Returns:: The inner characteristics.
Return type:: Sequence[Characteristic]

property explanation: Optional[str]

Get the explanation.

Returns:: The strategy explanation.
Return type:: Optional[str]

property label: Optional[str]

Get the label.

Returns:: The strategy label.
Return type:: Optional[str]

class Named(name: str, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any)

The Named class is used to represent named characteristics.

Is is designed for subclassing.

__call__(individual: Any) → Optional[Any]

Make this characteristic callable.

This method should be overridden in sub-classes.

Parameters:: individual (object) – Any python object.
Returns:: The individual characteristic.
Return type:: Optional[Any]

Hint

If the returned value is None, the characteristic is undetermined.

__init__(name: str, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any) → None

Initialise a Named instance.

Parameters:

characteristic (Characteristic) – The inner characteristic (if any)
**kwargs – Unused but useful for multi-class inheritance.

Keyword Arguments:

name – A name (usually a string)

property cache: bool

Get the cache property.

Returns:: The cache property.
Return type:: bool

property characteristic: Optional[galactic.characteristics.Characteristic]

Get the inner characteristic.

Returns:: The inner characteristic.
Return type:: Characteristic

clear() → None: Clear the cache.

property components: Sequence[galactic.characteristics.Characteristic]

Get the inner characteristics.

Returns:: The inner characteristics.
Return type:: Sequence[Characteristic]

property explanation: Optional[str]

Get the explanation.

Returns:: The strategy explanation.
Return type:: Optional[str]

property label: Optional[str]

Get the label.

Returns:: The strategy label.
Return type:: Optional[str]

property name: str

Get the name.

Returns:: The name.
Return type:: str

class Key(name: str, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any)

The Key class is used to represent key characteristics.

Example

>>> from galactic.characteristics import Key
>>> a = Key(name="x")
>>> print(a)
x
>>> a({"x": 5})
5
>>> a({})
>>> a=Key(name="y", characteristic=Key(name="x"))
>>> print(a)
x[y]
>>> a({"x": {"y": 5}})
5

__call__(individual: Any) → Optional[Any]

Make this characteristic callable.

This method should be overridden in sub-classes.

Parameters:: individual (object) – Any python object.
Returns:: The individual characteristic.
Return type:: Optional[Any]

Hint

If the returned value is None, the characteristic is undetermined.

__init__(name: str, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any) → None

Initialise a Named instance.

Parameters:

characteristic (Characteristic) – The inner characteristic (if any)
**kwargs – Unused but useful for multi-class inheritance.

Keyword Arguments:

name – A name (usually a string)

property cache: bool

Get the cache property.

Returns:: The cache property.
Return type:: bool

property characteristic: Optional[galactic.characteristics.Characteristic]

Get the inner characteristic.

Returns:: The inner characteristic.
Return type:: Characteristic

clear() → None: Clear the cache.

property components: Sequence[galactic.characteristics.Characteristic]

Get the inner characteristics.

Returns:: The inner characteristics.
Return type:: Sequence[Characteristic]

property explanation: Optional[str]

Get the explanation.

Returns:: The strategy explanation.
Return type:: Optional[str]

property label: Optional[str]

Get the label.

Returns:: The strategy label.
Return type:: Optional[str]

property name: str

Get the name.

Returns:: The name.
Return type:: str

class Property(name: str, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any)

The Property class is used to represent property characteristics.

__call__(individual: Any) → Optional[Any]

Make this characteristic callable.

This method should be overridden in sub-classes.

Parameters:: individual (object) – Any python object.
Returns:: The individual characteristic.
Return type:: Optional[Any]

Hint

If the returned value is None, the characteristic is undetermined.

__init__(name: str, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any) → None

Initialise a Named instance.

Parameters:

characteristic (Characteristic) – The inner characteristic (if any)
**kwargs – Unused but useful for multi-class inheritance.

Keyword Arguments:

name – A name (usually a string)

property cache: bool

Get the cache property.

Returns:: The cache property.
Return type:: bool

property characteristic: Optional[galactic.characteristics.Characteristic]

Get the inner characteristic.

Returns:: The inner characteristic.
Return type:: Characteristic

clear() → None: Clear the cache.

property components: Sequence[galactic.characteristics.Characteristic]

Get the inner characteristics.

Returns:: The inner characteristics.
Return type:: Sequence[Characteristic]

property explanation: Optional[str]

Get the explanation.

Returns:: The strategy explanation.
Return type:: Optional[str]

property label: Optional[str]

Get the label.

Returns:: The strategy label.
Return type:: Optional[str]

property name: str

Get the name.

Returns:: The name.
Return type:: str

class Item(nth: int = 0, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any)

The Item class is used to represent item sequences.

Example

>>> from galactic.characteristics import Item, Key
>>> a = Item(nth=1)
>>> print(a)
~[1]
>>> a([1, 2, 3])
2
>>> a([])
>>> a = Item(nth=1, characteristic=Key(name="a"))
>>> print(a)
a[1]

__call__(individual: Any) → Optional[Any]

Make this characteristic callable.

This method should be overridden in sub-classes.

Parameters:: individual (object) – Any python object.
Returns:: The individual characteristic.
Return type:: Optional[Any]

Hint

If the returned value is None, the characteristic is undetermined.

__init__(nth: int = 0, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any) → None

Initialise a Item instance.

Keyword Arguments:

nth (int) – The numbering of the element in the sequence.
characteristic (Characteristic) – The inner characteristic if any

property cache: bool

Get the cache property.

Returns:: The cache property.
Return type:: bool

property characteristic: Optional[galactic.characteristics.Characteristic]

Get the inner characteristic.

Returns:: The inner characteristic.
Return type:: Characteristic

clear() → None: Clear the cache.

property components: Sequence[galactic.characteristics.Characteristic]

Get the inner characteristics.

Returns:: The inner characteristics.
Return type:: Sequence[Characteristic]

property explanation: Optional[str]

Get the explanation.

Returns:: The strategy explanation.
Return type:: Optional[str]

property label: Optional[str]

Get the label.

Returns:: The strategy label.
Return type:: Optional[str]

property nth: int

Get the nth value.

Returns:: The nth value.
Return type:: int

class Slice(start: Optional[int] = None, end: Optional[int] = None, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any)

The Slice class is used to represent item slices.

Example

>>> from galactic.characteristics import Slice, Key
>>> a = Slice(start=1)
>>> print(a)
~[1:]
>>> a([1, 2, 3])
[2, 3]
>>> a(None)
>>> a = Slice(start=1, characteristic=Key(name="a"))
>>> print(a)
a[1:]

__call__(individual: Any) → Optional[Any]

Make this characteristic callable.

This method should be overridden in sub-classes.

Parameters:: individual (object) – Any python object.
Returns:: The individual characteristic.
Return type:: Optional[Any]

Hint

If the returned value is None, the characteristic is undetermined.

__init__(start: Optional[int] = None, end: Optional[int] = None, characteristic: Optional[galactic.characteristics.Characteristic] = None, **kwargs: Any) → None

Initialise a Slice instance.

Keyword Arguments:

start (int) – The slice start.
end (int) – The slice end.
characteristic (Characteristic) – The inner characteristic (if any).

property cache: bool

Get the cache property.

Returns:: The cache property.
Return type:: bool

property characteristic: Optional[galactic.characteristics.Characteristic]

Get the inner characteristic.

Returns:: The inner characteristic.
Return type:: Characteristic

clear() → None: Clear the cache.

property components: Sequence[galactic.characteristics.Characteristic]

Get the inner characteristics.

Returns:: The inner characteristics.
Return type:: Sequence[Characteristic]

property end: Optional[int]

Get the end property.

Returns:: The end property.
Return type:: Optional[int]

property explanation: Optional[str]

Get the explanation.

Returns:: The strategy explanation.
Return type:: Optional[str]

property label: Optional[str]

Get the label.

Returns:: The strategy label.
Return type:: Optional[str]

property start: Optional[int]

Get the start property.

Returns:: The start property.
Return type:: Optional[int]