The functions provided by Tensorflow to create tf.train.Feature protocol buffer messages

features.py

def _bytes_feature(value):
    """Returns a bytes_list from a string / byte."""
    # If the value is an eager tensor BytesList won't unpack a string from an EagerTensor.
    if isinstance(value, type(tf.constant(0))):
        value = value.numpy() 
    return tf.train.Feature(bytes_list=tf.train.BytesList(value=[value]))

def _float_feature(value):
    """Returns a float_list from a float / double."""
    return tf.train.Feature(float_list=tf.train.FloatList(value=[value]))

def _int64_feature(value):
    """Returns an int64_list from a bool / enum / int / uint."""
    return tf.train.Feature(int64_list=tf.train.Int64List(value=[value]))