"""
Write a program that takes a list of words and groups together the anagrams.
"""
from collections import Counter, defaultdict


def group_by(col, hashfn=None):
  if not hashfn:
    hashfn = hash  # builtin hash
  group = defaultdict(list)
  [group[hashfn(e)].append(e) for e in col]

  return group.values()


def anagram_hash(word):
  return tuple(sorted(Counter(word)))


group_by(["hello", "foo", "olleh", "bar", "baz", "arb"], hashfn=anagram_hash)
# [["hello", "olleh"], ["foo"], ["bar", "arb"], ["baz"]]