Add/remove custom stop words with spacy

You can edit them before processing your text like this (see this post):

>>> import spacy
>>> nlp = spacy.load("en")
>>> nlp.vocab["the"].is_stop = False
>>> nlp.vocab["definitelynotastopword"].is_stop = True
>>> sentence = nlp("the word is definitelynotastopword")
>>> sentence[0].is_stop
False
>>> sentence[3].is_stop
True

Note: This seems to work <=v1.8. For newer versions, see other answers.

Using Spacy 2.0.11, you can update its stopwords set using one of the following:

To add a single stopword:

import spacy    
nlp = spacy.load("en")
nlp.Defaults.stop_words.add("my_new_stopword")

To add several stopwords at once:

import spacy    
nlp = spacy.load("en")
nlp.Defaults.stop_words |= {"my_new_stopword1","my_new_stopword2",}

To remove a single stopword:

import spacy    
nlp = spacy.load("en")
nlp.Defaults.stop_words.remove("whatever")

To remove several stopwords at once:

import spacy    
nlp = spacy.load("en")
nlp.Defaults.stop_words -= {"whatever", "whenever"}

Note: To see the current set of stopwords, use:

print(nlp.Defaults.stop_words)

Update : It was noted in the comments that this fix only affects the current execution. To update the model, you can use the methods nlp.to_disk("/path") and nlp.from_disk("/path") (further described at https://spacy.io/usage/saving-loading).