tensorflow输入x和y拟合线性曲线，求k,b

import numpy as np
import tensorflow as tf
x_data=np.random.rand(1000)
y_data=x_data*10 +77

print(x_data)
print(y_data)

k=tf.Variable(0.,name='k')
b=tf.Variable(0.)
y=k*x_data+b

loss = tf.reduce_mean(tf.square(y-y_data))
optimizer = tf.train.GradientDescentOptimizer(0.2)
train = optimizer.minimize(loss)

init=tf.global_variables_initializer()

with tf.Session() as sess:
    sess.run(init)
    for step in range(201):
        sess.run(train)
        if step%20==0:
            k1,b1 = sess.run([k, b])
            mess='step:%s,k:%s,b:%s'%(step,k1,b1)
            print(mess)
            print([k1,b1])