human
Complete the below
def _encoded_image_string_tensor_input_placeholder():

    ''''Returns input that accepts a batch of PNG or JPEG strings.
    Returns:
    a tuple of placeholder and input nodes that output decoded images.'
    '''

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Give me a the Python code you requested?
assistant
#Here is the Python code you requested.
    batch_image_str_placeholder = tf.placeholder(dtype=tf.string, shape=[None], name='encoded_image_string_tensor')
    def decode(encoded_image_string_tensor):
        image_tensor = tf.image.decode_image(encoded_image_string_tensor, channels=3)
        image_tensor.set_shape((None, None, 3))
        return image_tensor
    return (batch_image_str_placeholder, tf.map_fn(decode, elems=batch_image_str_placeholder, dtype=tf.uint8, parallel_iterations=32, back_prop=False))