Tensorflow Input Data Protocol Buffer (tf.train.example) Typeerror For Feature With String Type

I am trying to encode my data as tf.train.Example according to tensorflow's tutorial. I have a string value that I want to pass to the Features property of the Example class and I

Solution 1:

It seems that they expect s1 to be a byte string, so you need to add b before the ":

import tensorflow as tf
tf_example = tf.train.Example()
s1 = b"sample string 1"
tf_example.features.feature['str1'].bytes_list.value.extend([s1])