使用 tensorflow 提取 ELMo 特征并将其转换为 numpy

Question

So I am interested to extract sentence embeddings using ELMo model.

I tried this at first:

import tensorflow as tf
import tensorflow_hub as hub
import numpy as np

elmo_model = hub.Module("https://tfhub.dev/google/elmo/2", trainable=True)

x = ["Hi my friend"]

embeddings = elmo_model(x, signature="default", as_dict=True)["elmo"]


print(embeddings.shape)
print(embeddings.numpy())

It works well until the last line, that I could not convert it to numpy array.

I searched a little and I found if I put the following line in the beginning of my codes, the problem must be solved.

tf.enable_eager_execution()

However, I put this at the beginning of my code, I realized I could not compile the

elmo_model = hub.Module("https://tfhub.dev/google/elmo/2", trainable=True)

I received this error:

 Exporting/importing meta graphs is not supported when eager execution is enabled. No graph exists when eager execution is enabled.

How can I solve my problem? My goal is to obtain sentence features and use them in NumPy array.

Thanks in advance

Answer 1

TF 2.x

TF2 behavior is closer to the classic python behavior, because it defaults to eager execution. However, you should use hub.load to load your model in TF2.

elmo = hub.load("https://tfhub.dev/google/elmo/2").signature["default"]
x = ["Hi my friend"]
embeddings = elmo(tf.constant(x))["elmo"]

Then, you can access the results and convert them to numpy array using the numpy method.

>>> embeddings.numpy()
array([[[-0.7205108 , -0.27990735, -0.7735629 , ..., -0.24703965,
         -0.8358178 , -0.1974785 ],
        [ 0.18500198, -0.12270843, -0.35163105, ...,  0.14234722,
          0.08479916, -0.11709933],
        [-0.49985904, -0.88964033, -0.30124515, ...,  0.15846594,
          0.05210422,  0.25386307]]], dtype=float32)

TF 1.x

If using TF 1.x, you should run the operation inside a tf.Session . TensorFlow does not use eager execution and requires to first build the graph, and then evaluate the results inside a session.

elmo_model = hub.Module("https://tfhub.dev/google/elmo/2", trainable=True)
x = ["Hi my friend"]
embeddings_op = elmo_model(x, signature="default", as_dict=True)["elmo"]
# required to load the weights into the graph
init_op = tf.global_variables_initializer()

with tf.Session() as sess:
    sess.run(init_op)
    embeddings = sess.run(embeddings_op)

In that case, the result will already be a numpy array:

>>> embeddings
array([[[-0.72051036, -0.27990723, -0.773563  , ..., -0.24703972,
         -0.83581805, -0.19747877],
        [ 0.18500218, -0.12270836, -0.35163072, ...,  0.14234722,
          0.08479934, -0.11709933],
        [-0.49985906, -0.8896401 , -0.3012453 , ...,  0.15846589,
          0.05210405,  0.2538631 ]]], dtype=float32)