Spacy errors and their solutions

 Introduction:

There are a bunch of errors in spacy, which never makes sense until you get to the depth of it. In this post, we will analyze the attribute error E046 and why it occurs.

(1)

AttributeError: [E046] Can't retrieve unregistered extension attribute 'tag_name'. Did you forget to call the set_extension method?

Let's first understand what the error means on superficial level. There is a tag_name extension in your code. i.e. from a doc object, probably you are calling doc._.tag_name. But spacy suggests to you that probably you forgot to call the set_extension method. So what to do from here?

The problem in hand is that your extension is not created where it should have been created. Now in general this means that your pipeline is incorrect at some level. 

So how should you solve it?

Look into the pipeline of your spacy language object. Chances are that the pipeline component which creates the extension is not included in the pipeline. To check the pipe element; use nlp.pipe_names for seeing the pipe elements. Now if you find out that all the pipe elements are there, then reason the extension is not created is clearly your pipe element orders are not correct. It can often happen from adding custom components in a wrong place. For example, if you call ner tagger before sentencizer; then each sentence document will not have associated ners. So it is important to check the orders of your components and put them serially based on their dependencies. 

These are the only 2 main ways to solve this issue.

(2) 

KeyError: "[E002] Can't find factory for 'tagger'. This usually happens when spaCy calls `nlp.create_pipe` with a component name that's not built in - for example, when constructing the pipeline from a model's meta.json. If you're using a custom component, you can write to `Language.factories['tagger']` or remove it from the model meta and add it via `nlp.add_pipe` instead."

This is another common error. Although it looks like a very complicated error; you may have no error in your code. This error occurs for me when I use spyder IDE with spacy code. If you run the same models loading twice within a spyder IDE, then this error comes. Currently according to github issues and suggestions in this error's thread; you should restart the kernel and run the code afresh. The error will not reoccur.

References:

(1) git issue 3590

(2) git issue 3569

(3) remove element from spacy pipeline