An example of Tf.where usage is like this:

```
import tensorflow as tf
import os
os.environ["TF_CPP_MIN_LOG_LEVEL"] = "2"
# Constants (3-element arrays).
a = tf.constant([100, 200, 300])
b = tf.constant([1, 2, 3])
# Use placeholder for predicate to where.
# ... We pass in an array of 3 bools to fill the placeholder.
j = tf.placeholder(tf.bool, [3])
# Use where to apply 1 of 2 methods based on each predicate.
# ... First argument is the predicate (contains bools).
# Second argument is run when true.
# Third argument is run when false.
x = tf.where(j, a + 5000, a + b)
# Run with 3 bools in placeholder.
array_temp = [False, True, False]
result = tf.Session().run(x, {j: array_temp})
# For false, add 2 elements toe get her.
# ... For true, add 5000 to first element.
print(result)
```

Not sure if there is something that can do the same job like tf.where in this case.