How to convert .ckpt to .pb?

Following the answer of @Puneith Kaul, here is the syntax for tensorflow version 1.7:

import os
import tensorflow as tf

export_dir = 'export_dir' 
trained_checkpoint_prefix = 'models/model.ckpt'
graph = tf.Graph()
loader = tf.train.import_meta_graph(trained_checkpoint_prefix + ".meta" )
sess = tf.Session()
loader.restore(sess,trained_checkpoint_prefix)
builder = tf.saved_model.builder.SavedModelBuilder(export_dir)
builder.add_meta_graph_and_variables(sess, [tf.saved_model.tag_constants.TRAINING, tf.saved_model.tag_constants.SERVING], strip_default_attrs=True)
builder.save()

Here's the code to convert the checkpoint to SavedModel

import os
import tensorflow as tf

trained_checkpoint_prefix = 'models/model.ckpt-49491'
export_dir = os.path.join('export_dir', '0')

graph = tf.Graph()
with tf.compat.v1.Session(graph=graph) as sess:
    # Restore from checkpoint
    loader = tf.compat.v1.train.import_meta_graph(trained_checkpoint_prefix + '.meta')
    loader.restore(sess, trained_checkpoint_prefix)

    # Export checkpoint to SavedModel
    builder = tf.compat.v1.saved_model.builder.SavedModelBuilder(export_dir)
    builder.add_meta_graph_and_variables(sess,
                                         [tf.saved_model.TRAINING, tf.saved_model.SERVING],
                                         strip_default_attrs=True)
    builder.save()