代码摘自：-http : //adventuresinmachinelearning.com/python-tensorflow-tutorial/
import tensorflow as tf
from tensorflow.examples.tutorials.mnist import input_data
mnist = input_data.read_data_sets("MNIST_data/", one_hot=True)
# Python optimisation variables
learning_rate = 0.5
epochs = 10
batch_size = 100
# declare the training data placeholders
# input x - for 28 x 28 pixels = 784
x = tf.placeholder(tf.float32, [None, 784])
# now declare the output data placeholder - 10 digits
y = tf.placeholder(tf.float32, [None, 10])
# now declare the weights connecting the input to the hidden layer
W1 = …