Abstract class enforced (#521)

* gitignore cleaned and re-organised

* LayerConfig Abstract Class enforced as Abstract

* LayersConfig unittest added

* Py2 and Py3 compatibility issue fixed

Author: DEKHTIARJonathan

.gitignore

@@ -2,15 +2,19 @@
 *.npz
 *.pyc
 *~
+
 .DS_Store
 .idea
 .spyproject/
+.pytest_cache/
+
+venv/
 build/
-dist
+data/
+dist/
 docs/_build
 tensorlayer.egg-info
-tensorlayer/__pacache__
-venv/
-.pytest_cache/
+tensorlayer/__pycache__
+
 update_tl.bat
 update_tl.py

tensorlayer/layers/core.py

@@ -1,6 +1,8 @@
 # -*- coding: utf-8 -*-
 
+import six
 import time
+from abc import ABCMeta, abstractmethod
 
 import numpy as np
 import tensorflow as tf
@@ -38,10 +40,16 @@
 ]
 
 
-class LayersConfig:
+@six.add_metaclass(ABCMeta)
+class LayersConfig(object):
+
     tf_dtype = tf.float32  # TensorFlow DType
     set_keep = {}  # A dictionary for holding tf.placeholders
 
+    @abstractmethod
+    def __init__(self):
+        pass
+
 
 try:  # For TF12 and later
     TF_GRAPHKEYS_VARIABLES = tf.GraphKeys.GLOBAL_VARIABLES

tests/test_layers_core.py

@@ -6,6 +6,16 @@
 import tensorlayer as tl
 
 
+class Core_Helpers_Test(unittest.TestCase):
+
+    def test_LayersConfig(self):
+        with self.assertRaises(TypeError):
+            tl.layers.LayersConfig()
+
+        self.assertIsInstance(tl.layers.LayersConfig.tf_dtype, tf.DType)
+        self.assertIsInstance(tl.layers.LayersConfig.set_keep, dict)
+
+
 class Layer_Core_Test(unittest.TestCase):
 
     @classmethod