gensim word2vec print log loss

Question

how to print to log (file or stout) the loss of each epoch in the training phase, when using gensim word2vec model.

I tried :

 logging.basicConfig(format='%(asctime)s: %(levelname)s: %(message)s')
 logging.root.setLevel(level=logging.INFO)

But I didn't saw any loss printing.

Answer 1

You can get the latest training loss of a word2vec model with the method get_latest_training_loss(). If you want to print the loss after every epoch you can add a callback that does this. For example:

from gensim.test.utils import common_texts, get_tmpfile
from gensim.models import Word2Vec
from gensim.models.callbacks import CallbackAny2Vec

class callback(CallbackAny2Vec):
    '''Callback to print loss after each epoch.'''

    def __init__(self):
        self.epoch = 0

    def on_epoch_end(self, model):
        loss = model.get_latest_training_loss()
        print('Loss after epoch {}: {}'.format(self.epoch, loss))
        self.epoch += 1

model = Word2Vec(common_texts, size=100, window=5, min_count=1, 
                 compute_loss=True, callbacks=[callback()])

However, the loss is computed in a cumulative way (i.e. the loss that gets printed after each epoch is the total loss of all epochs so far). See gojomo's answer here for more explanation.