Remove examples from pybind wrapper (#698)

* Remove examples from pybind wrapper
* Adding back example (basic.py)

python/examples/mnist_mlp.py

-#!/usr/bin/env python
-# ******************************************************************************
-# Copyright 2017-2018 Intel Corporation
-#
-# 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.
-# ******************************************************************************
-from ngraph.impl import Type, Function
-from ngraph.impl import Node, Shape, AxisVector, AxisSet
-from ngraph.impl.op import Parameter, Maximum, Reshape, Dot, Broadcast
-from ngraph.impl.op import Constant, Exp, Log, Sum
-from ngraph.impl.op import Greater, Convert, Reduce
-from ngraph.impl.op import OneHot
-
-from typing import List, Dict, Set
-
-
-float_element_type = Type.f32
-int_element_type = Type.i32
-bz = 53
-lr = 0.2
-
-Input = Parameter(float_element_type, Shape([bz, 28, 28]))
-Label = Parameter(int_element_type, Shape([bz]))
-LabelOneHot = Convert((OneHot(Label, Shape([bz, 10]), 1)), float_element_type)
-
-MaxParam1 = Parameter(float_element_type, Shape([]))
-MaxParam2 = Parameter(float_element_type, Shape([]))
-MaxFn = Function(Maximum(MaxParam1, MaxParam2),
-                 [MaxParam1, MaxParam2],
-                 'mnist')
-
-
-def make_scalar_constant(elem_type, scalar, shape=None, axis_set=None):
-    # type: (int, float, List[int], Set[int]) -> float
-    """Create a Constant node for scalar value."""
-    if shape is None:
-        shape = Shape([])
-    if axis_set is None:
-        axis_set = AxisSet(set())
-    scalar_shape = Shape([])  # type: List[int]
-    constant_op = Constant(elem_type, scalar_shape, [scalar])
-    constant_broadcast = Broadcast(constant_op, shape, axis_set)
-    return constant_broadcast
-
-
-def make_float32_constant(scalar, shape=None, axis_set=None):
-    # type: (float, List[int], Set[int]) -> float
-    """Create a Constant node for float value."""
-    if shape is None:
-        shape = []
-    if axis_set is None:
-        axis_set = set()
-    return make_scalar_constant(Type.f32, scalar, Shape(shape), AxisSet(axis_set))
-
-
-def make_float32_constant_like(scalar, op):  # type: (float, Node) -> float
-    """Create a Constant node for float value."""
-    v = set()
-    shape = op.get_shape()
-    for i in range(len(shape)):
-        v.add(i)
-    return make_float32_constant(scalar, Shape(shape), AxisSet(v))
-
-
-def transpose(op, order):  # type: (Node, List[int]) -> Node
-    """Transpose data via reshape."""
-    v = []
-    for i in range(len(order)):
-        v.append(op.get_shape()[order[i]])
-    new_shape = v
-    return Reshape(op, AxisVector(order), Shape(new_shape))
-
-
-def relu(op):  # type: (Node) -> Node
-    """Relu operator."""
-    return Maximum(op, make_float32_constant_like(0., op))
-
-
-# Flatten
-X1 = Reshape(Input, AxisVector([0, 1, 2]), Shape([bz, 784]))
-
-# Normalize
-X2 = X1 / make_float32_constant_like(255., X1)
-
-# Affine 1
-W1 = Parameter(float_element_type, Shape([784, 100]))
-b1 = Parameter(float_element_type, Shape([100]))
-X3 = Dot(X2, W1) + Broadcast(b1, Shape([bz, 100]), AxisSet({0}))
-X4 = relu(X3)
-
-# Affine 2
-W2 = Parameter(float_element_type, Shape([100, 10]))
-b2 = Parameter(float_element_type, Shape([10]))
-X5 = Dot(X4, W2) + Broadcast(b2, Shape([bz, 10]), AxisSet({0}))
-
-# Softmax
-Logits = X5
-Exp = Exp(Logits)
-Max = Reduce(Exp, make_float32_constant(0., [], set()), MaxFn, AxisSet({1}))
-MaxBroadcast = Broadcast(Max, Shape([bz, 10]), AxisSet({1}))
-Softmax = Exp / MaxBroadcast
-
-# Loss
-LogSoftmax = Log(Softmax)
-Loss = Sum(LogSoftmax * LabelOneHot, AxisSet({0, 1})) / make_float32_constant(float(bz), [], set())
-
-# Derivatives
-dLogits = Softmax - LabelOneHot
-dX5 = dLogits
-
-dX4 = Dot(dX5, transpose(W2, Shape([1, 0])))
-dW2 = Dot(transpose(X4, Shape([1, 0])), dX5)
-db2 = Sum(dX5, AxisSet({0}))
-
-dX3 = Convert((Greater(X3, make_float32_constant(0., [bz, 100], {0, 1}))), float_element_type) * dX4
-dX2 = Dot(dX3, transpose(W1, Shape([1, 0])))
-dW1 = Dot(transpose(X2, Shape([1, 0])), dX3)
-db1 = Sum(dX3, AxisSet({0}))
-
-nW1 = W1 - make_float32_constant_like(lr, dW1) * dW1
-nb1 = b1 - make_float32_constant_like(lr, db1) * db1
-nW2 = W2 - make_float32_constant_like(lr, dW2) * dW2
-nb2 = b2 - make_float32_constant_like(lr, db2) * db2