Constraint

class jwst.associations.lib.constraint.Constraint(init=None, reduce=None, name=None, reprocess_on_match=False, reprocess_on_fail=False, work_over=ListCategory.BOTH, reprocess_rules=None)[source]

Bases: object

Constraint that is made up of SimpleConstraints.

Attributes:

constraints[Constraint[,…]]: List of Constraint or SimpleConstraint that make this constraint.
matchedbool: Result of the last check_and_set
reducefunction: A reduction function with signature x(iterable) where iterable is the components list. Returns boolean indicating state of the components. Predefined functions are: - all: True if all components return True - any: True if any component returns True

Notes

Named constraints can be accessed directly through indexing:

>>> c = Constraint(SimpleConstraint(name="simple", value="a_value"))
>>> c["simple"]
SimpleConstraint({'sources': <function SimpleConstraint.__init__.<locals>.<lambda>,
                  'force_unique': True,
                  'test': <bound method SimpleConstraint.eq of SimpleConstraint({...})>,
                  'reprocess_on_match': False,
                  'reprocess_on_fail': False,
                  'work_over': 1,
                  'reprocess_rules': None,
                  'value': 'a_value',
                  'name': 'simple',
                  'matched': False})

Initialize a new Constraint.

Parameters:

initobject or [object[,…]]: A single object or list of objects where the objects are as follows. - SimpleConstraint or subclass - Constraint
reducefunction: A reduction function with signature x(iterable) where iterable is the components list. Returns boolean indicating state of the components. Default value is Constraint.all
namestr or None: Optional name for constraint.
reprocess_on_matchbool: Reprocess the item if the constraint is satisfied.
reprocess_on_failbool: Reprocess the item if the constraint is not satisfied.
work_overListCategory.[BOTH, EXISTING, RULES]: The condition on which this constraint should operate.
reprocess_rules[rule[,..]] or None: List of rules to be applied to. If None, calling function will determine the ruleset. If empty, [], all rules will be used.

Attributes Summary

`dup_names`	Return dictionary of constraints with duplicate names.
`id`	Return identifier for the constraint.

Methods Summary

`all`(item, constraints)	Return positive only if all results are positive.
`any`(item, constraints)	Return the first successful constraint.
`append`(constraint)	Append a new constraint.
`check_and_set`(item[, work_over])	Check and set the constraint.
`copy`()	Copy ourselves.
`get_all_attr`(attribute[, name])	Return the specified attribute for specified constraints.
`notall`(item, constraints)	Check if not all of the constraints match; true if not all do.
`notany`(item, constraints)	Check if none of the constraints match; true if none do.
`preserve`()	Preserve all constraint states.
`restore`()	Restore all constraint states.

Attributes Documentation

dup_names

Return dictionary of constraints with duplicate names.

This method is meant to be overridden by classes that need to traverse a list of constraints.

Returns:

dups{str: [constraint[,…]][,…]}: Returns a mapping between the duplicated name and all the constraints that define that name.

id

Return identifier for the constraint.

Returns:

idstr: The identifier

Methods Documentation

static all(item, constraints)[source]

Return positive only if all results are positive.

Parameters:

itemACID: The candidate.
constraintslist[Constraint, …]: The list of constraints to check.

Returns:

bool, list(Constraint, …) or None: True if all constraints positive, with empty list. If no constraints, False and empty list. Otherwise False with list of constraints to reprocess.

static any(item, constraints)[source]

Return the first successful constraint.

Parameters:

itemACID: The candidate.
constraintslist[Constraint, …]: The list of constraints to check.

Returns:

bool, list(Constraint, …) or None: False, [] if no match or constraints to reprocess. True, list(Constraints) if match found, and any constraints to reprocess listed.

append(constraint)[source]: Append a new constraint.

check_and_set(item, work_over=ListCategory.BOTH)[source]

Check and set the constraint.

Returns:

success, reprocessbool, [~jwst.associations.ProcessList[,…]]

Returns 2-tuple of

success : True if check is successful.

List of ProcessList.

copy()[source]

Copy ourselves.

Returns:

object: Deepcopy of self.

get_all_attr(attribute, name=None)[source]

Return the specified attribute for specified constraints.

Parameters:

attributestr: The attribute to retrieve
namestr or None: Only return attribute if the name of the current constraint matches the requested named constraints. If None, always return value.

Returns:

result[(SimpleConstraint or Constraint, object)[,…]]: The list of values of the attribute in a tuple. If there is no attribute, an empty tuple is returned.

Raises:

AttributeError: If the attribute is not found.

static notall(item, constraints)[source]

Check if not all of the constraints match; true if not all do.

Parameters:

itemACID: The candidate.
constraintslist[Constraint, …]: The list of constraints to check.

Returns:

bool: True if not all constraints match.

static notany(item, constraints)[source]

Check if none of the constraints match; true if none do.

Parameters:

itemACID: The candidate.
constraintslist[Constraint, …]: The list of constraints to check.

Returns:

bool: True if none of the constraints match.

preserve()[source]: Preserve all constraint states.

restore()[source]: Restore all constraint states.