Add readthedocs.yaml file.

docs/conf.py

@@ -36,7 +36,7 @@
 # readthedocs path
 sys.path.insert(2, '/home/docs/checkouts/readthedocs.org/user_builds/rlgraph/checkouts/latest/rlgraph')
 
-import rlgraph as rl
+from rlgraph.version import __version__
 
 
 # -- Project information -----------------------------------------------------
@@ -46,9 +46,9 @@
 author = 'RLgraph authors'
 
 # The short X.Y version
-version = re.sub(r'\.\d+$', "", rl.__version__)
+version = re.sub(r'\.\d+$', "", __version__)
 # The full version, including alpha/beta/rc tags
-release = rl.__version__
+release = __version__
 
 
 # -- General configuration ---------------------------------------------------

readthedocs.yaml

@@ -0,0 +1,23 @@
+# Copyright 2018 The RLgraph authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+
+
+python:
+  version: 3.5
+  setup_py_install: true
+  extra_requirements:
+    - tensorflow
+    - ray
+    - gym

rlgraph/__init__.py

@@ -121,9 +121,10 @@ def emit(self, record):
     try:
         import tensorflow
     except ModuleNotFoundError as e:
-        raise ValueError("INIT ERROR: Cannot run distributed_tf without backend (tensorflow)! "
-                         "Please install tensorflow first via `pip install tensorflow` or "
-                         "`pip install tensorflow-gpu`.")
+        raise ModuleNotFoundError(
+            "INIT ERROR: Cannot run distributed_tf without backend (tensorflow)! Please install tensorflow first "
+            "via `pip install tensorflow` or `pip install tensorflow-gpu`."
+        )
 elif DISTRIBUTED_BACKEND == "horovod":
     try:
         import horovod