BeforeChildDispatcher

(class from pyomo.repn.util)

class pyomo.repn.util.BeforeChildDispatcher[source]

Bases: defaultdict

Dispatcher for handling the StreamBasedExpressionVisitor beforeChild callback

This dispatcher implements a specialization of defaultdict that supports automatic type registration. Any missing types will return the register_dispatcher() method, which (when called as a callback) will interrogate the type, identify the appropriate callback, add the callback to the dict, and return the result of calling the callback. As the callback is added to the dict, no type will incur the overhead of register_dispatcher more than once.

Note that all dispatchers are implemented as staticmethod functions to avoid the (unnecessary) overhead of binding to the dispatcher object.

__init__(*args, **kwargs)

Methods

`__init__`(args, *kwargs)
`clear`()
`copy`()
`fromkeys`([value])	Create a new dictionary with keys from iterable and values set to value.
`get`(key[, default])	Return the value for key if key is in the dictionary, else default.
`items`()
`keys`()
`pop`(k[,d])	If the key is not found, return the default if given; otherwise, raise a KeyError.
`popitem`()	Remove and return a (key, value) pair as a 2-tuple.
`register_dispatcher`(visitor, child)
`setdefault`(key[, default])	Insert key with a value of default if key is not in the dictionary.
`update`([E, ]**F)	If E is present and has a .keys() method, then does: for k in E: D[k] = E[k] If E is present and lacks a .keys() method, then does: for k, v in E: D[k] = v In either case, this is followed by: for k in F: D[k] = F[k]
`values`()

Attributes

default_factory

Factory for default value called by __missing__().

Member Documentation

clear() → None. Remove all items from D.

copy() → a shallow copy of D.

fromkeys(value=None, /): Create a new dictionary with keys from iterable and values set to value.

get(key, default=None, /): Return the value for key if key is in the dictionary, else default.

items() → a set-like object providing a view on D's items

keys() → a set-like object providing a view on D's keys

pop(k[, d]) → v, remove specified key and return the corresponding value.: If the key is not found, return the default if given; otherwise, raise a KeyError.

popitem()

Remove and return a (key, value) pair as a 2-tuple.

Pairs are returned in LIFO (last-in, first-out) order. Raises KeyError if the dict is empty.

setdefault(key, default=None, /)

Insert key with a value of default if key is not in the dictionary.

Return the value for key if key is in the dictionary, else default.

update([E, ]**F) → None. Update D from dict/iterable E and F.: If E is present and has a .keys() method, then does: for k in E: D[k] = E[k] If E is present and lacks a .keys() method, then does: for k, v in E: D[k] = v In either case, this is followed by: for k in F: D[k] = F[k]

values() → an object providing a view on D's values

default_factory: Factory for default value called by __missing__().