Part of twisted.python.constants View Source View In Hierarchy
Known subclasses: twisted.python.constants.Names, twisted.python.constants.Values
_ConstantsContainer
is a class with attributes used as symbolic constants. It is up to
subclasses to specify what kind of constants are allowed.Method | __new__ | Classes representing constants containers are not intended to be instantiated. |
Class Method | lookupByName | Retrieve a constant by its name or raise a ValueError if
there is no constant associated with that name. |
Class Method | iterconstants | Iteration over a Names subclass
results in all of the constants it contains. |
Class Variable | _constantType | Specified by a _ConstantsContainer
subclass to specify the type of constants allowed by that subclass. |
Class Variable | _enumerantsInitialized | A bool tracking whether _enumerants has been
initialized yet or not. |
Class Variable | _enumerants | A dict mapping the names of constants (eg NamedConstant
instances) found in the class definition to those instances. This is
initialized via the _EnumerantsInitializer
descriptor the first time it is accessed. |
Class Method | _initializeEnumerants | Find all of the NamedConstant
instances in the definition of cls , initialize them with
constant values, and build a mapping from their names to them to attach to
cls . |
Class Method | _constantFactory | Construct the value for a new constant to add to this container. |
_ConstantsContainer
subclass to specify the type of constants allowed by that subclass.
dict
mapping the names of constants (eg NamedConstant
instances) found in the class definition to those instances. This is
initialized via the _EnumerantsInitializer
descriptor the first time it is accessed.
The class object itself is used directly.
NamedConstant
instances in the definition of cls
, initialize them with
constant values, and build a mapping from their names to them to attach to
cls
.Parameters | name | The name of the constant to create. |
Returns | NamedConstant
instances have no value apart from identity, so return a meaningless dummy
value. |
ValueError
if
there is no constant associated with that name.Parameters | name | A str giving the name of one of the constants defined by
cls . |
Returns | The NamedConstant
associated with name . | |
Raises | ValueError | If name is not the name of one of the constants defined by
cls . |
Names
subclass
results in all of the constants it contains.Returns | an iterator the elements of which are the NamedConstant
instances defined in the body of this Names subclass. |