nltk.featstruct.FeatList

class documentation

class FeatList(FeatStruct, list): (source)

Constructor: FeatList(features, **morefeatures)

A list of feature values, where each feature value is either a basic value (such as a string or an integer), or a nested feature structure.

Feature lists may contain reentrant feature values. A "reentrant feature value" is a single feature value that can be accessed via multiple feature paths. Feature lists may also be cyclic.

Two feature lists are considered equal if they assign the same values to all features, and have the same reentrances.

See Also
`FeatStruct` for information about feature paths, reentrance, cyclic feature structures, mutability, freezing, and hashing.

Method	`__deepcopy__`	Undocumented
Method	`__delitem__`	If the feature with the given name or path exists, delete its value; otherwise, raise `KeyError`.
Method	`__getitem__`	Undocumented
Method	`__init__`	Create a new feature list, with the specified features.
Method	`__setitem__`	Set the value for the feature with the given name or path to `value`. If `name_or_path` is an invalid path, raise `KeyError`.
Class Variable	`__iadd__`	Undocumented
Class Variable	`__imul__`	Undocumented
Class Variable	`append`	Undocumented
Class Variable	`extend`	Undocumented
Class Variable	`insert`	Undocumented
Class Variable	`pop`	Undocumented
Class Variable	`remove`	Undocumented
Class Variable	`reverse`	Undocumented
Class Variable	`sort`	Undocumented
Method	`_items`	Return an iterable of (fid,fval) pairs, where fid is a feature identifier and fval is the corresponding feature value, for all features defined by this FeatStruct.
Method	`_keys`	Return an iterable of the feature identifiers used by this FeatStruct.
Method	`_repr`	Return a string representation of this feature structure.
Method	`_values`	Return an iterable of the feature values directly defined by this FeatStruct.
Constant	`_INDEX_ERROR`	Undocumented

Inherited from FeatStruct:

Method	`__eq__`	Return true if `self` and `other` are both feature structures, assign the same values to all features, and contain the same reentrances. I.e., return `self.equal_values(other, check_reentrance=True)`.
Method	`__hash__`	If this feature structure is frozen, return its hash value; otherwise, raise `TypeError`.
Method	`__lt__`	Undocumented
Method	`__ne__`	Undocumented
Method	`__new__`	Construct and return a new feature structure. If this constructor is called directly, then the returned feature structure will be an instance of either the `FeatDict` class or the `FeatList` class.
Method	`__repr__`	Display a single-line representation of this feature structure, suitable for embedding in other representations.
Method	`copy`	Return a new copy of `self`. The new copy will not be frozen.
Method	`cyclic`	Return True if this feature structure contains itself.
Method	`equal_values`	Return True if `self` and `other` assign the same value to to every feature. In particular, return true if `self[p]==other[p]` for every feature path p such that `self[p]` or `other[p]` is a base value (i.e., not a nested feature structure).
Method	`freeze`	Make this feature structure, and any feature structures it contains, immutable. Note: this method does not attempt to 'freeze' any feature value that is not a `FeatStruct`; it is recommended that you use only immutable feature values.
Method	`frozen`	Return True if this feature structure is immutable. Feature structures can be made immutable with the `freeze()` method. Immutable feature structures may not be made mutable again, but new mutable copies can be produced with the ...
Method	`remove_variables`	Return the feature structure that is obtained by deleting any feature whose value is a `Variable`.
Method	`rename_variables`	No summary
Method	`retract_bindings`	No summary
Method	`substitute_bindings`	No summary
Method	`subsumes`	Return True if `self` subsumes `other`. I.e., return true If unifying `self` with `other` would result in a feature structure equal to `other`.
Method	`unify`	Undocumented
Method	`variables`	No summary
Method	`walk`	Return an iterator that generates this feature structure, and each feature structure it contains. Each feature structure will be generated exactly once.
Method	`_calculate_hashvalue`	Return a hash value for this feature structure.
Method	`_equal`	Return True iff self and other have equal values.
Method	`_find_reentrances`	Return a dictionary that maps from the `id` of each feature structure contained in `self` (including `self`) to a boolean value, indicating whether it is reentrant or not.
Method	`_freeze`	Make this feature structure, and any feature structure it contains, immutable.
Method	`_walk`	Undocumented
Constant	`_FROZEN_ERROR`	Undocumented
Instance Variable	`_frozen`	frozen or not. Once this flag is set, it should never be un-set; and no further modification should be made to this feature structue.
Instance Variable	`_hash`	Undocumented

def __deepcopy__(self, memo): (source) ¶

overrides nltk.featstruct.FeatStruct.__deepcopy__

Undocumented

def __delitem__(self, name_or_path): (source) ¶

If the feature with the given name or path exists, delete its value; otherwise, raise KeyError.

def __getitem__(self, name_or_path): (source) ¶

Undocumented

def __init__(self, features=()): (source) ¶

Create a new feature list, with the specified features.

Parameters
features	The initial list of features for this feature list. If `features` is a string, then it is paresd using `FeatStructReader`. Otherwise, it should be a sequence of basic values and nested feature structures.

def __setitem__(self, name_or_path, value): (source) ¶

Set the value for the feature with the given name or path to value. If name_or_path is an invalid path, raise KeyError.

__iadd__ = (source) ¶

Undocumented

__imul__ = (source) ¶

Undocumented

append = (source) ¶

Undocumented

extend = (source) ¶

Undocumented

insert = (source) ¶

Undocumented

pop = (source) ¶

Undocumented

remove = (source) ¶

Undocumented

reverse = (source) ¶

Undocumented

sort = (source) ¶

Undocumented

def _items(self): (source) ¶

overrides nltk.featstruct.FeatStruct._items

Return an iterable of (fid,fval) pairs, where fid is a feature identifier and fval is the corresponding feature value, for all features defined by this FeatStruct.

def _keys(self): (source) ¶

overrides nltk.featstruct.FeatStruct._keys

Return an iterable of the feature identifiers used by this FeatStruct.

def _repr(self, reentrances, reentrance_ids): (source) ¶

overrides nltk.featstruct.FeatStruct._repr

Return a string representation of this feature structure.

Parameters
reentrances	A dictionary that maps from the `id` of each feature value in self, indicating whether that value is reentrant or not.
reentrance_ids	A dictionary mapping from each `id` of a feature value to a unique identifier. This is modified by `repr`: the first time a reentrant feature value is displayed, an identifier is added to `reentrance_ids` for it.

def _values(self): (source) ¶

overrides nltk.featstruct.FeatStruct._values

Return an iterable of the feature values directly defined by this FeatStruct.

_INDEX_ERROR: str = (source) ¶

Undocumented

Value

'Expected int or feature path.  Got %r.'