utils.py

import functools

from functional import compose, partial
import tensorflow as tf


def composeAll(*args):
    """Util for multiple function composition

    i.e. composed = composeAll([f, g, h])
         composed(x) == f(g(h(x)))
    """
    # adapted from https://docs.python.org/3.1/howto/functional.html
    return partial(functools.reduce, compose)(*args)

def print_(var, name: str, first_n=5, summarize=5):
    """Util for debugging, by printing values of tf.Variable `var` during training"""
    # (tf.Tensor, str, int, int) -> tf.Tensor
    return tf.Print(var, [var], "{}: ".format(name), first_n=first_n,
                    summarize=summarize)

def get_mnist(n, mnist):
    """Returns 784-D numpy array for random MNIST digit `n`"""
    assert 0 <= n <= 9, "Must specify digit 0 - 9!"
    import random

    SIZE = 500
    imgs, labels = mnist.train.next_batch(SIZE)
    idxs = iter(random.sample(range(SIZE), SIZE)) # non-in-place shuffle

    for i in idxs:
        if labels[i] == n:
            return imgs[i] # first match