In this article, we will guide you through the process of implementing an Out-Of-Vocabulary (OOV) spelling correction system using the Transformers library. This is particularly useful when dealing with misspelled words that are not present in your model’s training set. Let’s dive into the steps!
Prerequisites
Make sure you have the following:
- Python installed on your system.
- The Transformers library, which you can install via pip:
pip install transformers
pip install torch
Loading the Model and Tokenizer
First, we need to load the model and tokenizer required for spelling correction. This involves downloading the appropriate resources. Here’s a breakdown of the code for downloading and loading the model:
from transformers import EncoderDecoderModel
from importlib.machinery import SourceFileLoader
from transformers.file_utils import cached_path, hf_bucket_url
import torch
import os
cache_dir = '.cache'
model_name = 'nguyenvulebinh/spelling-oov'
def download_tokenizer_files():
resources = ['envibert_tokenizer.py', 'dict.txt', 'sentencepiece.bpe.model']
for item in resources:
if not os.path.exists(os.path.join(cache_dir, item)):
tmp_file = hf_bucket_url(model_name, filename=item)
tmp_file = cached_path(tmp_file, cache_dir=cache_dir)
os.rename(tmp_file, os.path.join(cache_dir, item))
download_tokenizer_files()
spell_tokenizer = SourceFileLoader('envibert.tokenizer', os.path.join(cache_dir, 'envibert_tokenizer.py')).load_module().RobertaTokenizer(cache_dir)
spell_model = EncoderDecoderModel.from_pretrained(model_name)
In this code, think of the process as preparing for a big party. First, you collect all the necessary items (data) you need to host the event (run your model).
Defining the Spelling Correction Function
Now that we have our model and tokenizer loaded, we can define the function for OOV spelling correction:
def oov_spelling(word, num_candidate=1):
result = []
inputs = spell_tokenizer([word.lower()])
input_ids = inputs['input_ids']
attention_mask = inputs['attention_mask']
inputs = {
'input_ids': torch.tensor(input_ids),
'attention_mask': torch.tensor(attention_mask)
}
outputs = spell_model.generate(**inputs, num_return_sequences=num_candidate)
for output in outputs.cpu().detach().numpy().tolist():
result.append(spell_tokenizer.sp_model.DecodePieces(spell_tokenizer.decode(output, skip_special_tokens=True).split()))
return result
# Example usage
output = oov_spelling("spacespeaker")
print(output) # output: [x pây x pếch cơ]
This function is like having a smart assistant who suggests corrections for a misspelled word. It takes the word as input, processes it, and gives you back one or more suggestions. It uses the attention mask to focus on the relevant parts, similar to how you would concentrate on the main topic at a meeting while being aware of background information.
How to Troubleshoot
If you encounter issues while implementing this code, consider the following troubleshooting ideas:
- Ensure all necessary libraries are installed correctly.
- Check for any typos in the model name or resource files.
- If downloading files fails, ensure you have a stable internet connection.
- For any unexpected errors, run each segment of the code separately to identify where the issue originates.
- For more insights, updates, or to collaborate on AI development projects, stay connected with fxis.ai.
At fxis.ai, we believe that such advancements are crucial for the future of AI, as they enable more comprehensive and effective solutions. Our team is continually exploring new methodologies to push the envelope in artificial intelligence, ensuring that our clients benefit from the latest technological innovations.
Conclusion
Congratulations! You’ve successfully set up an OOV spelling correction system using the Transformers library. This capability opens up a lot of possibilities for enhancing text processing applications. Keep experimenting with different words and configurations to see how your system performs!

