BPEmb

BPEmb is a collection of pre-trained subword embeddings in 275 languages, based on Byte-Pair Encoding (BPE) and trained on Wikipedia. Its intended use is as input for neural models in natural language processing.

Website ・ Usage ・ Download ・ MultiBPEmb ・ Paper (pdf) ・ Citing BPEmb

Usage

Install BPEmb with pip:

pip install bpemb

Embeddings and SentencePiece models will be downloaded automatically the first time you use them.

>>> from bpemb import BPEmb
# load English BPEmb model with default vocabulary size (10k) and 50-dimensional embeddings
>>> bpemb_en = BPEmb(lang="en", dim=50)
downloading https://nlp.h-its.org/bpemb/en/en.wiki.bpe.vs10000.model
downloading https://nlp.h-its.org/bpemb/en/en.wiki.bpe.vs10000.d50.w2v.bin.tar.gz

You can do two main things with BPEmb. The first is subword segmentation:

# apply English BPE subword segmentation model
>>> bpemb_en.encode("Stratford")
['▁strat', 'ford']
# load Chinese BPEmb model with vocabulary size 100k and default (100-dim) embeddings
>>> bpemb_zh = BPEmb(lang="zh", vs=100000)
# apply Chinese BPE subword segmentation model
>>> bpemb_zh.encode("这是一个中文句子")  # "This is a Chinese sentence."
['▁这是一个', '中文', '句子']  # ["This is a", "Chinese", "sentence"]

If / how a word gets split depends on the vocabulary size. Generally, a smaller vocabulary size will yield a segmentation into many subwords, while a large vocabulary size will result in frequent words not being split:

The second purpose of BPEmb is to provide pretrained subword embeddings:

# Embeddings are wrapped in a gensim KeyedVectors object
>>> type(bpemb_zh.emb)
gensim.models.keyedvectors.Word2VecKeyedVectors
# You can use BPEmb objects like gensim KeyedVectors
>>> bpemb_en.most_similar("ford")
[('bury', 0.8745079040527344),
 ('ton', 0.8725000619888306),
 ('well', 0.871537446975708),
 ('ston', 0.8701574206352234),
 ('worth', 0.8672043085098267),
 ('field', 0.859795331954956),
 ('ley', 0.8591548204421997),
 ('ington', 0.8126075267791748),
 ('bridge', 0.8099068999290466),
 ('brook', 0.7979353070259094)]
>>> type(bpemb_en.vectors)
numpy.ndarray
>>> bpemb_en.vectors.shape
(10000, 50)
>>> bpemb_zh.vectors.shape
(100000, 100)

To use subword embeddings in your neural network, either encode your input into subword IDs:

>>> ids = bpemb_zh.encode_ids("这是一个中文句子")
[25950, 695, 20199]
>>> bpemb_zh.vectors[ids].shape
(3, 100)

Or use the embed method:

# apply Chinese subword segmentation and perform embedding lookup
>>> bpemb_zh.embed("这是一个中文句子").shape
(3, 100)

GitHub - bheinzerling/bpemb at pythonawesome.com

Pre-trained subword embeddings in 275 languages, based on Byte-Pair Encoding (BPE) - GitHub - bheinzerling/bpemb at pythonawesome.com

GitHubbheinzerling