Package nltk_lite :: Package contrib :: Module marshalbrill :: Class Brill
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Class Brill

source code

     object --+        
              |        
yaml.YAMLObject --+    
                  |    
           tag.TagI --+
                      |
                     Brill

Brill's transformational rule-based tagger. Brill taggers use an initial tagger (such as tag.Default) to assign an intial tag sequence to a text; and then apply an ordered list of transformational rules to correct the tags of individual tokens. These transformation rules are specified by the BrillRuleI interface.

Brill taggers can be created directly, from an initial tagger and a list of transformational rules; but more often, Brill taggers are created by learning rules from a training corpus, using either BrillTrainer or FastBrillTrainer.

Nested Classes [hide private]

Inherited from yaml.YAMLObject: __metaclass__, yaml_dumper, yaml_loader

Instance Methods [hide private]
 
__init__(self, initial_tagger, rules)
x.__init__(...) initializes x; see x.__class__.__doc__ for signature
source code
 
rules(self) source code
 
tag(self, tokens)
Assign a tag to each token in tokens, and yield a tagged token of the form (token, tag)
source code
 
marshal(self, filename)
Marshals (saves to a plain text file) the tagger model.
source code
 
unmarshal(self, filename)
Unmarshals (loads from a plain text file) the tagger model.
source code

Inherited from object: __delattr__, __getattribute__, __hash__, __new__, __reduce__, __reduce_ex__, __repr__, __setattr__, __str__

Class Methods [hide private]

Inherited from yaml.YAMLObject: from_yaml, to_yaml

Class Variables [hide private]
  _classname = 'BrillTagger'

Inherited from yaml.YAMLObject: yaml_flow_style, yaml_tag

Properties [hide private]

Inherited from object: __class__

Method Details [hide private]

__init__(self, initial_tagger, rules)
(Constructor)

source code 

x.__init__(...) initializes x; see x.__class__.__doc__ for signature

Parameters:
  • initial_tagger (TagI) - The initial tagger
  • rules (list of BrillRuleI) - An ordered list of transformation rules that should be used to correct the initial tagging.
Overrides: object.__init__

tag(self, tokens)

source code 

Assign a tag to each token in tokens, and yield a tagged token of the form (token, tag)

Overrides: tag.TagI.tag
(inherited documentation)

marshal(self, filename)

source code 

Marshals (saves to a plain text file) the tagger model.

Parameters:
  • filename (string) - Name of the file to which save the model (will be overwritten if it already exists).

unmarshal(self, filename)

source code 

Unmarshals (loads from a plain text file) the tagger model. This operation will override any previously stored rules.

Parameters:
  • filename (string) - Name of the file from which the model will be read.