官网定义的结构为：
tf.zeros(
shape,
dtype=tf.float32,
name=None
)shape代表形状，也就是1纬的还是2纬的还是n纬的数组。
下面看图说话：
1. 一维数组里放一个值
import tensorflow as tf
res = tf.random_uniform((4, 4), -1, 1)
res2 = tf.zeros([1])
with tf.Session() as sess:
print(sess.run(res2))
#结果为：
[0.]
2. 一维数组里放两个值
import tensorflow as tf
res = tf.random_uniform((4, 4), -1, 1)
res2 = tf.zeros([2])
with tf.Session() as sess:
print(sess.run(res2))
#结果为：
[0. 0.]
3. 二维数组
import tensorflow as tf
res = tf.random_uniform((4, 4), -1, 1)
res2 = tf.zeros([2, 4])
with tf.Session() as sess:
print(sess.run(res2))
#结果为：
[[0. 0. 0. 0.]
[0. 0. 0. 0.]]