TypeError: 'Tensor' object cannot be interpreted as an integer

Not really sure what you want to achieve here. loop is a tf.Tensor and range expects an integer as argument, hence the error. If you just want to print a 5 times, why don't you just set loop to the numerical value of 5?

Otherwise, the following code should work, as loop.eval() returns the value of loop which is 5:

a = tf.Variable([1,2,3,4,5],dtype = tf.int32)
loop = tf.size(a)
....
for i in range(loop.eval()):
    print(sess.run(a))

If you don't want to execute the TF graph multiple times, take a look at tf.while_loop.

tf.size() does not give you a value or list.

a = tf.Variable([1,2,3,4,5],dtype = tf.int32)

v = a.get_shape()
loop = v.num_elements()

...

Perhaps, try this.