splitting position and tokens embeddings in OpenAI GPT - updating tf imports - tests

pytorch_pretrained_bert/modeling.py

@@ -52,6 +52,14 @@ TF_WEIGHTS_NAME = 'model.ckpt'
 def load_tf_weights_in_bert(model, tf_checkpoint_path):
     """ Load tf checkpoints in a pytorch model
     """
+    try:
+        import re
+        import numpy as np
+        import tensorflow as tf
+    except ModuleNotFoundError:
+        print("Loading a TensorFlow models in PyTorch, requires TensorFlow to be installed. Please see "
+            "https://www.tensorflow.org/install/ for installation instructions.")
+        raise
     tf_path = os.path.abspath(tf_checkpoint_path)
     print("Converting TensorFlow checkpoint from {}".format(tf_path))
     # Load weights from TF model