test suite independent of framework

pytorch_transformers/__init__.py

@@ -43,11 +43,11 @@ from .configuration_distilbert import DistilBertConfig, DISTILBERT_PRETRAINED_CO
 # Modeling
 try:
     import torch
-    torch_available = True  # pylint: disable=invalid-name
+    _torch_available = True  # pylint: disable=invalid-name
 except ImportError:
-    torch_available = False  # pylint: disable=invalid-name
+    _torch_available = False  # pylint: disable=invalid-name
 
-if torch_available:
+if _torch_available:
     logger.info("PyTorch version {} available.".format(torch.__version__))
 
     from .modeling_utils import (PreTrainedModel, prune_layer, Conv1D)
@@ -87,19 +87,26 @@ if torch_available:
 # TensorFlow
 try:
     import tensorflow as tf
-    tf_available = True  # pylint: disable=invalid-name
+    assert int(tf.__version__[0]) >= 2
+    _tf_available = True  # pylint: disable=invalid-name
 except ImportError:
-    tf_available = False  # pylint: disable=invalid-name
+    _tf_available = False  # pylint: disable=invalid-name
 
-if tf_available:
+if _tf_available:
     logger.info("TensorFlow version {} available.".format(tf.__version__))
 
     from .modeling_tf_utils import TFPreTrainedModel
     from .modeling_tf_bert import (TFBertPreTrainedModel, TFBertModel, TFBertForPreTraining,
-                                TFBertForMaskedLM, TFBertForNextSentencePrediction, load_pt_weights_in_bert)
+                                   TFBertForMaskedLM, TFBertForNextSentencePrediction, load_bert_pt_weights_in_tf)
 
 
 # Files and general utilities
 from .file_utils import (PYTORCH_TRANSFORMERS_CACHE, PYTORCH_PRETRAINED_BERT_CACHE,
                          cached_path, add_start_docstrings, add_end_docstrings,
                          WEIGHTS_NAME, TF_WEIGHTS_NAME, CONFIG_NAME)
+
+def is_torch_available():
+    return _torch_available
+
+def is_tf_available():
+    return _tf_available