py-galactic

py-galactic is a package for studying Formal Concept Analysis.

Install py-galactic

py-galactic requires python 3, a programming language that comes pre-installed on linux and Mac OS X, and which is easily installed on Windows.

Install py-galactic using the bash command

pip install py-galactic

To upgrade to the most recent release, use

pip install --upgrade py-galactic

pip is a script that downloads and installs modules from the Python Package Index, PyPI. It should come installed with your python distribution. If you are running linux, pip may be bundled separately. On a Debian-based system (including Ubuntu), you can install it using

apt-get update
apt-get install python-pip

Getting Help

Important

If you have any difficulties with py-galactic, please feel welcome to file an issue on github so that we can help.

Context

The galactic.context package defines generic classes for using contexts:

• Context: a context is composed by a population and a model
• Population a population is a container for individuals
• Model a model is a container for attributes
• Individual an individual has an identifier and values
• Attribute an attribute has a name and a type

class galactic.context.C

Generic subclass of the Context class

class galactic.context.P

Generic subclass of the Population class

class galactic.context.M

Generic subclass of the Model class

class galactic.context.X

Generic subclass of the Individual class

class galactic.context.A

Generic subclass of the Attribute class

class galactic.context.Context

A Context handles a model and a population.

It’s possible to access to the context population attribute or to the context model attribute.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> print(context.population)
['0', '1']
>>> print(context.model)
{'mybool': <class 'bool'>, 'myint': <class 'int'>}

It’s possible to check if a context is not empty (both model and population are not empty) using the python builtin bool() function.

It’s possible to get a readable representation of a context using the python builtin str() function.

Example

>>> print(context)
{'population': ['0', '1'], 'model': {'mybool': <class 'bool'>, 'myint': <class 'int'>}}

Example

>>> bool(context)
True

Contexts are container for individuals and attributes. It’s possible to know if an individual or an attribute belongs to a context using the python in keyword.

Example

>>> context.model['mybool'] in context
True
>>> context.population['0'] in context
True

New in version 0.0.1.

population

Get the population for this context.

Returns:the underlying population Return type:P

New in version 0.0.1.

model

Get the underlying model.

Returns:the underlying model Return type:M

New in version 0.0.1.

class galactic.context.Population

A Population is a container for individuals.

It’s possible to access to the population context attribute.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> population = context.population
>>> print(population.context)
{'population': ['0', '1'], 'model': {'mybool': <class 'bool'>, 'myint': <class 'int'>}}

It’s possible to get a readable representation of a population.

Example

>>> print(population)
['0', '1']

It’s possible to check if a population is not empty using the python builtin bool() function.

Example

>>> bool(population)
True

It’s possible to access to an individual with its identifier using the python array access construct.

Example

>>> print(population['0'])
{'mybool': False, 'myint': 0}

It’s possible to check if an individual belongs to a population using the python in keyword.

Example

>>> '0' in population
True

It’s possible to iterate over a population using the python for keyword.

Example

>>> {ident: str(individual) for ident, individual in population.items()}
{'0': "{'mybool': False, 'myint': 0}", '1': "{'mybool': False, 'myint': 0}"}

It’s possible to get the length of a population using the python builtin len() function.

Example

>>> len(population)
2

New in version 0.0.1.

context

Get the underlying context.

Returns:the underlying context Return type:C

New in version 0.0.1.

model

Get the underlying model.

Returns:the underlying model Return type:M

New in version 0.0.1.

class galactic.context.Model

A Model is a container for attributes.

It’s possible to access to the model context attribute.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> model = context.model
>>> print(model.context)
{'population': ['0', '1'], 'model': {'mybool': <class 'bool'>, 'myint': <class 'int'>}}

It’s possible to get a readable representation of a model using the python builtin str() function.

Example

>>> print(model)
{'mybool': <class 'bool'>, 'myint': <class 'int'>}

It’s possible to check if a model is not empty using the python builtin bool() function.

Example

>>> bool(model)
True

It’s possible to access to an attribute with its name using the python array access construct.

Example

>>> print(model['mybool'])
{'name': 'mybool', 'type': <class 'bool'>}

It’s possible to check if an attribute belongs to a model using the python in keyword.

Example

>>> 'mybool' in model
True

It’s possible to iterate over a model using the python for keyword.

Example

>>> {name: attribute.type for name, attribute in model.items()}
{'mybool': <class 'bool'>, 'myint': <class 'int'>}

It’s possible to get the length of a population using the python builtin len() function.

Example

>>> len(model)
2

New in version 0.0.1.

context

Get the underlying context.

Returns:the underlying context Return type:C

New in version 0.0.1.

population

Get the underlying population.

Returns:the underlying population Return type:P

New in version 0.0.1.

class galactic.context.Individual

A Individual is a container for values.

It’s possible to access to the individual identifier attribute.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> individual = context.population['0']
>>> individual.identifier
'0'

It’s possible to access to the individual context attribute.

Example

>>> print(individual.context)
{'population': ['0', '1'], 'model': {'mybool': <class 'bool'>, 'myint': <class 'int'>}}

It’s possible to access to the individual model attribute.

Example

>>> print(individual.model)
{'mybool': <class 'bool'>, 'myint': <class 'int'>}

It’s possible to access to the individual population attribute.

Example

>>> print(individual.population)
['0', '1']

It’s possible to get a readable representation of an individual using the python builtin str() function.

Example

>>> print(individual)
{'mybool': False, 'myint': 0}

It’s possible to access to the individual values using the value() method.

Example

>>> attribute = individual.model['mybool']
>>> individual.value(attribute)
False

It’s possible to access to the individual values using the python array access construct.

Example

>>> individual['mybool']
False

It’s possible to get the length of an individual using the python builtin len() function.

Example

>>> len(individual)
2

It’s possible to iterate over an individual using the python for keyword.

Example

>>> {name: value for name, value in individual.items()}
{'mybool': False, 'myint': 0}

New in version 0.0.1.

identifier

Get this individual identifier.

Returns:the individual identifier Return type:str

New in version 0.0.1.

population

Get the underlying population.

Returns:the underlying population Return type:P

New in version 0.0.1.

context

Get the underlying context.

Returns:the underlying context Return type:C

New in version 0.0.1.

model

Get the underlying model.

Returns:the underlying model Return type:M

New in version 0.0.1.

value(attribute: A)

Get the attribute value for this individual.

Parameters:attribute (A) – the attribute Returns:the value Return type:object Raises:ValueError – if the attribute does not belong to the underlying model.

New in version 0.0.1.

class galactic.context.Attribute

A Attribute is described by a name and a type.

It’s possible to access to the attribute identifier and type attributes.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> attribute = context.model['mybool']
>>> attribute.name
'mybool'
>>> attribute.type
<class 'bool'>

It’s possible to access to the individual context attribute.

Example

>>> print(attribute.context)
{'population': ['0', '1'], 'model': {'mybool': <class 'bool'>, 'myint': <class 'int'>}}

It’s possible to access to the individual model attribute.

Example

>>> print(attribute.model)
{'mybool': <class 'bool'>, 'myint': <class 'int'>}

It’s possible to access to the individual population attribute.

Example

>>> print(attribute.population)
['0', '1']

It’s possible to get a readable representation of an attribute using the python builtin str() function.

Example

>>> print(attribute)
{'name': 'mybool': 'type': <class 'bool'>}

It’s possible to access to the attribute values using the value() method.

Example

>>> individual = attribute.population['0']
>>> attribute.value(individual)
False

It’s possible to access to the attribute values using the python array access construct.

Example

>>> attribute['0']
False

It’s possible to get the length of an attribute using the python builtin len() function.

Example

>>> len(attribute)
2

It’s possible to iterate over an attribute using the python for keyword.

Example

>>> {identifier: value for identifier, value in attribute.items()}
{'0': False, '1': False}

New in version 0.0.1.

name

Get the attribute name.

Returns:the attribute name Return type:str

New in version 0.0.1.

type

Get the attribute type.

Returns:the attribute type Return type:type

New in version 0.0.1.

model

Get the underlying model.

Returns:the underlying model Return type:M

New in version 0.0.1.

context

Get the underlying context.

Returns:the underlying context Return type:C

New in version 0.0.1.

population

Get the underlying population.

Returns:the underlying population Return type:P

New in version 0.0.1.

value(individual: X)

Get the individual value for this attribute.

Parameters:individual (X) – the individual Returns:the value Return type:object Raises:ValueError – if the individual does not belong to the underlying population.

New in version 0.0.1.

Mixins

The galactic.context.mixins package defines mixins classes for defining new types of contexts:

• ConcreteIndividual for defining individuals that own their identifier as a field
• ConcreteAttribute for defining attributes that own their name and their type as fields
• ContextHolder for defining elements that own their context as a field
• PopulationHolder for defining elements that own their population as a field
• ModelHolder for defining elements that own their model as a field
• AttributesHolder for defining models that own their attributes as a field
• IndividualsHolder for defining population that own their individuals as a field
• ValuesHolder for defining individuals that own their values as a field

They are widely used for defining

• MemoryContext
• MemoryModel
• MemoryPopulation
• MemoryAttribute
• MemoryIndividual

in the galactic.context.memory package.

New in version 0.0.1.

class galactic.context.mixins.ConcreteIndividual(**kwargs)

The ConcreteIndividual class is a mixin used in subclassing the Individual class for storing their identifier as a field.

New in version 0.0.1.

__init__(**kwargs)

Initialise an individual.

Keyword Arguments:  identifier (str) – the individual identifier

New in version 0.0.1.

identifier

Get the individual identifier.

Returns:the individual identifier Return type:str

New in version 0.0.1.

class galactic.context.mixins.ConcreteAttribute(**kwargs)

The ConcreteAttribute class is a mixin used in subclassing the Attribute class for storing their name and their type as a class.

New in version 0.0.1.

__init__(**kwargs)

Initialise an attribute

Keyword Arguments:  

• name (str) – the attribute name
• type (type) – the attribute type

New in version 0.0.1.

name

Get the attribute name.

Returns:the attribute name Return type:str

New in version 0.0.1.

type

Get the attribute type.

Returns:the attribute type Return type:type

New in version 0.0.1.

class galactic.context.mixins.ContextHolder(**kwargs)

The ContextHolder[C] is a mixin used for storing an element context as a field.

It’s a generic class that depends of a Context subclass C.

New in version 0.0.1.

__init__(**kwargs)

Initialise an element by setting its context.

Keyword Arguments:  context (C) – the context

New in version 0.0.1.

context

Get the context.

Returns:the context Return type:C

New in version 0.0.1.

class galactic.context.mixins.PopulationHolder(**kwargs)

The PopulationHolder[P] is a mixin used for storing an element population as a field.

It’s a generic class that depends of a Population subclass P.

New in version 0.0.1.

__init__(**kwargs)

Initialise an element by setting its population.

Keyword Arguments:  population (P) – the population

New in version 0.0.1.

population

Get the population.

Returns:the population Return type:P

New in version 0.0.1.

class galactic.context.mixins.ModelHolder(**kwargs)

The ModelHolder[M] class is a mixin used for storing an element model as a field.

It’s a generic class that depends of a Model subclass M.

New in version 0.0.1.

__init__(**kwargs)

Initialise an element by setting its model.

Keyword Arguments:  model (M) – the model

New in version 0.0.1.

model

Get the model.

Returns:the model Return type:M

New in version 0.0.1.

class galactic.context.mixins.AttributesHolder(**kwargs)

The AttributesHolder[A] class is a mixin used for storing the model attributes in memory.

It’s a generic class that depends of an Attribute subclass A.

New in version 0.0.1.

__init__(**kwargs)

Initialise an attribute holder.

Keyword Arguments:  attributes (Iterable[A]) – the attributes

New in version 0.0.1.

class galactic.context.mixins.IndividualsHolder(**kwargs)

The IndividualsHolder[X] class is a mixin used for storing the population individuals in memory.

It’s a generic class that depends of an Individual subclass X.

New in version 0.0.1.

__init__(**kwargs)

Initialise an individuals holder.

Keyword Arguments:  individuals (Iterable[A]) – the individuals

New in version 0.0.1.

class galactic.context.mixins.ValuesHolder(**kwargs)

The ValuesHolder[A] class is a mixin for storing the individual values in memory.

It’s a generic class that depends of an Attribute subclass A.

New in version 0.0.1.

__init__(**kwargs)

Initialise a values holder.

Keyword Arguments:  values (Mapping[str, object]) – the initial (name, value) pairs

New in version 0.0.1.

MemoryContext

The galactic.context.memory module give the ability to define Context that resides in memory.

class galactic.context.memory.MemoryContext(**kwargs)

The MemoryContext class is designed to define contexts in memory. It inherits of all the behavior from the Context class and allows direct creation and modification of a context.

It’s possible to create a context without nothing.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext()
>>> print(context)
{'population': [], 'model': {}}

It’s possible to create a context specifying the model definition.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(definition={'mybool': bool, 'myint': int})
>>> print(context)
{'population': [], 'model': {'mybool': <class 'bool'>, 'myint': <class 'int'>}}

It’s possible to create a context specifying the model definition and the list of individual identifiers.

Example

>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> print(context)
{'population': ['0', '1'], 'model': {'mybool': <class 'bool'>, 'myint': <class 'int'>}}

It’s possible to create a context specifying the model definition and the individual values.

Example

>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals={'0': {'mybool': True}, '1':{'myint': 1}}
... )
>>> {ident: str(context.population[ident]) for ident in context.population}
{'0': "{'mybool': True, 'myint': 0}", '1': "{'mybool': False, 'myint': 1}"}

New in version 0.0.1.

__init__(**kwargs)

Initialise a context in memory.

Keyword Arguments:  

• definition (Mapping[str, type]) – definition of the context by a mapping from name of attributes to their type
• individuals (Union[Iterable[str], Mapping[str, Mapping[str, object]]]) – initial iterable of individual identifiers or a mapping from individual identifiers to individual values

Raises:

• KeyError – if an attribute is not in the definition
• ValueError – if a value does not correspond to an attribute type
• TypeError – if the definition or if the individuals parameter are not of the correct type

New in version 0.0.1.

class galactic.context.memory.MemoryModel(context: galactic.context.memory.MemoryContext, definition: typing.Mapping[str, typing.type])

The MemoryModel class is designed to define models that resides in memory. It inherits of all the behavior from the Model class.

It’s possible to change or to set attribute values.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> model = context.model
>>> model['mybool'] = int
>>> model['myint2'] = int
>>> print(context.population['0'])
{'mybool': 0, 'myint': 0, 'myint2': 0}

It’s possible to delete an attribute using its name.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> model = context.model
>>> del model['mybool']
>>> {ident: str(context.population[ident]) for ident in context.population}
{'0': "{'myint': 0}", '1': "{'myint': 0}"}

New in version 0.0.1.

__init__(context: galactic.context.memory.MemoryContext, definition: typing.Mapping[str, typing.type])

Initialise a model in memory.

Parameters:

• context (MemoryContext) – the underlying context
• definition (Mapping[str, type]) – the attributes definition

New in version 0.0.1.

class galactic.context.memory.MemoryPopulation(context: galactic.context.memory.MemoryContext, identifiers: typing.Iterable[str])

The MemoryPopulation class is designed to define populations that resides in memory. It inherits of all the behavior from the Population class.

It’s possible to change or to set individual values.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> population = context.population
>>> population['0'] = {'mybool': True}
>>> population['2'] = {'myint': 1}
>>> print(population['0'])
{'mybool': True, 'myint': 0}
>>> print(population['2'])
{'mybool': False, 'myint': 1}

It’s possible to delete an individual using its identifier.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> population = context.population
>>> del population['0']
>>> {ident: str(context.population[ident]) for ident in context.population}
{'1': "{'mybool': False, 'myint': 0}"}

New in version 0.0.1.

__init__(context: galactic.context.memory.MemoryContext, identifiers: typing.Iterable[str])

Initialise a population in memory.

Parameters:

• context (MemoryContext) – the underlying context
• identifiers (Iterable[str]) – an iterable of identifiers

New in version 0.0.1.

class galactic.context.memory.MemoryIndividual(population: galactic.context.memory.MemoryPopulation, identifier: str)

The MemoryIndividual is designed to define individuals that resides in memory. It inherits of all the behavior from the Individual class.

It’s possible to modify a value for an individual using an attribute name.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> individual = context.population['0']
>>> individual['mybool'] = True
>>> individual['myint'] = 1
>>> {ident: str(context.population[ident]) for ident in context.population}
{'0': "{'mybool': True, 'myint': 1}", '1': "{'mybool': False, 'myint': 0}"}

New in version 0.0.1.

__init__(population: galactic.context.memory.MemoryPopulation, identifier: str)

Initialise an individual.

Parameters:

• population (MemoryPopulation) – the population
• identifier (str) – the individual identifier

New in version 0.0.1.

class galactic.context.memory.MemoryAttribute(model: galactic.context.memory.MemoryModel, name: str, cls: type)

The MemoryAttribute is designed to define attributes that resides in memory. It inherits of all the behavior from the Attribute class.

It’s possible to modify a value for an attribute using an individual identifier.

Example

>>> from galactic.context.memory import MemoryContext
>>> context = MemoryContext(
...     definition={'mybool': bool, 'myint': int},
...     individuals=['0', '1']
... )
>>> attribute = context.model['myint']
>>> attribute['0'] = 3
>>> attribute['1'] = 4
>>> {ident: str(context.population[ident]) for ident in context.population}
{'0': "{'mybool': False, 'myint': 3}", '1': "{'mybool': False, 'myint': 4}"}

New in version 0.0.1.

__init__(model: galactic.context.memory.MemoryModel, name: str, cls: type)

Initialise an attribute.

Parameters:

• model (MemoryModel) – the underlying model
• name (str) – the attribute name
• cls (type) – the attribute type

New in version 0.0.1.

Types

A type is associated to an Attribute. A type is valid if it is a class that can be called

• without argument: in that case a default value is returned for that type
• with an argument: in that case, the class try to convert it to an acceptable value for that type

For example the int and bool classes are acceptable types as they accept to be called without arguments or with an argument which is converted to the desired type.

Categories

Boolean

Number

This module one type useful in Context values:

• ImpreciseFloat for representing imprecise float as intervals.
• ImpreciseInteger for representing imprecise int as intervals.

class galactic.type.number.ImpreciseNumber(**kwargs)

The ImpreciseNumber class ca be used to represent intervals.

New in version 0.0.3.

classmethod default_lower()

Get the default lower limit for that class.

Returns:The default lower limit Return type:N

New in version 0.0.3.

classmethod default_upper()

Get the default upper limit for that class.

Returns:The default upper limit Return type:N

New in version 0.0.3.

classmethod convert(value)

Convert the value to the desired type.

Parameters:value – Value to be converted Returns:The default lower limit Return type:N

New in version 0.0.3.

__init__(**kwargs)

Initialise an ImpreciseNumber.

Keyword Arguments:  

• lower (N) – the lower limit of the interval
• upper (N) – the upper limit of the interval

New in version 0.0.2.

lower

Get the lower limit.

Returns:the lower limit Return type:N

New in version 0.0.2.

upper

Get the upper limit.

Returns:the upper limit Return type:N

New in version 0.0.2.

isdisjoint(other: galactic.type.number.ImpreciseNumber[N]) → bool

Return True if the imprecise number has no elements in common with the other. Imprecise numbers are disjoint if and only if their intersection is the empty imprecise number.

Parameters:other (ImpreciseNumber[N]) – the other imprecise number Returns:True if the imprecise number is disjoint from the other Return type:bool

New in version 0.0.2.

issubset(other: galactic.type.number.ImpreciseNumber[N]) → bool

Test if the imprecise number is included (or equal) to the other.

Parameters:other (ImpreciseNumber[N]) – Returns:True if this imprecise number is included or equal to the other Return type:bool

New in version 0.0.2.

issuperset(other: galactic.type.number.ImpreciseNumber[N]) → bool

Test if the imprecise number includes (or is equal to) the other.

Parameters:other (ImpreciseNumber[N]) – Returns:True if this imprecise number includes (or is equal to) the other Return type:bool

New in version 0.0.2.

union(*others) → galactic.type.number.ImpreciseNumber[N]

Compute the union between this imprecise number and the others.

Parameters:*others – Variable length argument list Returns:the union between this imprecise number and the others Return type:ImpreciseNumber[N]

New in version 0.0.2.

intersection(*others) → galactic.type.number.ImpreciseNumber[N]

Compute the intersection between this imprecise number and the others.

Parameters:*others – Variable length argument list Returns:the intersection between this imprecise number and the others Return type:ImpreciseNumber[N]

New in version 0.0.2.

class galactic.type.number.ImpreciseFloat(**kwargs)

ImpreciseFloat instances represents subset of the real line.

New in version 0.0.2.

classmethod convert(value)

Convert the value to a float.

Parameters:value – The value to convert Returns:The value converted Return type:float

New in version 0.0.3.

classmethod default_lower()

Get the default lower limit for that class.

Returns:The default lower limit is fixed to -math.inf Return type:float

New in version 0.0.3.

classmethod default_upper()

Get the default upper limit for that class.

Returns:The default upper limit is fixed to math.inf Return type:float

New in version 0.0.3.

class galactic.type.number.ImpreciseInteger(**kwargs)

ImpreciseInteger instances represents subset of the integer set.

New in version 0.0.3.

classmethod convert(value)

Convert the value to an int.

Parameters:value – The value to convert Returns:The value converted Return type:int

New in version 0.0.3.

classmethod default_lower()

Get the default lower limit for that class.

Returns:The default lower limit is fixed to -sys.maxsize Return type:int

New in version 0.0.3.

classmethod default_upper()

Get the default upper limit for that class.

Returns:The default upper limit is fixed to sys.maxsize Return type:int

New in version 0.0.3.

Indices and tables

• Index
• Module Index
• Search Page