title: Obtaining total number of records from .tfrecords file in Tensorflow
body: <p>Is it possible for obtain the total number of records from a <code>.tfrecords</code> file ? Related to this, how does one generally keep track of the number of epochs that have elapsed while training models? While it is possible for us to specify the <code>batch_size</code> and <code>num_of_epochs</code>, I am not sure if it is straightforward to obtain values such as <code>current epoch</code>, number of batches per epoch etc - just so that I could have more control of how the training is progressing. Currently, I'm just using a dirty hack to compute this as I know before hand how many records there are in my .tfrecords file and the size of my minibatches. Appreciate any help..</p>