Using Rasa NLU from python¶

Apart from running Rasa NLU as a HTTP server you can use it directly in your python program. Rasa NLU supports both Python 2 and 3.

Training Time¶

For creating your models, you can follow the same instructions as non-python users. Or, you can train directly in python with a script like the following (using spacy):

from rasa_nlu.training_data import load_data
from rasa_nlu.config import RasaNLUModelConfig
from rasa_nlu.model import Trainer
from rasa_nlu import config

training_data = load_data('data/examples/rasa/demo-rasa.json')
trainer = Trainer(config.load("sample_configs/config_spacy.yml"))
trainer.train(training_data)
model_directory = trainer.persist('./projects/default/')  # Returns the directory the model is stored in

Prediction Time¶

You can call Rasa NLU directly from your python script. To do so, you need to load the metadata of your model and instantiate an interpreter. The metadata.json in your model dir contains the necessary info to recover your model:

from rasa_nlu.model import Metadata, Interpreter

# where `model_directory points to the folder the model is persisted in
interpreter = Interpreter.load(model_directory)

You can then use the loaded interpreter to parse text:

interpreter.parse(u"The text I want to understand")

which returns the same dict as the HTTP api would (without emulation).

If multiple models are created, it is reasonable to share components between the different models. E.g. the 'nlp_spacy' component, which is used by every pipeline that wants to have access to the spacy word vectors, can be cached to avoid storing the large word vectors more than once in main memory. To use the caching, a ComponentBuilder should be passed when loading and training models.

Here is a short example on how to create a component builder, that can be reused to train and run multiple models, to train a model:

from rasa_nlu.training_data import load_data
from rasa_nlu import config
from rasa_nlu.components import ComponentBuilder
from rasa_nlu.model import Trainer

builder = ComponentBuilder(use_cache=True)      # will cache components between pipelines (where possible)

training_data = load_data('data/examples/rasa/demo-rasa.json')
trainer = Trainer(config.load("sample_configs/config_spacy.yml"), builder)
trainer.train(training_data)
model_directory = trainer.persist('./projects/default/')  # Returns the directory the model is stored in

The same builder can be used to load a model (can be a totally different one). The builder only caches components that are safe to be shared between models. Here is a short example on how to use the builder when loading models:

from rasa_nlu.model import Metadata, Interpreter
from rasa_nlu import config

# For simplicity we will load the same model twice, usually you would want to use the metadata of
# different models

interpreter = Interpreter.load(model_directory, builder)     # to use the builder, pass it as an arg when loading the model
# the clone will share resources with the first model, as long as the same builder is passed!
interpreter_clone = Interpreter.load(model_directory, builder)