      "    for char in string:\n",
      "        dict_chars[char] += 1\n",
      "    return dict_chars\n",
      "\n",
      "def permutations(str1, str2):\n",
      "    if len(str1) != len(str2):\n",
      "        return False\n",
      "    unique_counts1 = unique_counts(str1)\n",
      "    unique_counts2 = unique_counts(str2)\n",
      "    return unique_counts1 == unique_counts2\n",
 
</s> remove     "print(permutations('', 'foo'))\n",
    "print(permutations('Nib', 'bin'))\n",
    "print(permutations('act', 'cat'))\n",
    "print(permutations('a ct', 'ca t'))"
 </s> add     "run_tests(permutations)" </s> remove     "print(permutations('', 'foo'))\n",
    "print(permutations('Nib', 'bin'))\n",
    "print(permutations('act', 'cat'))\n",
    "print(permutations('a ct', 'ca t'))"
 </s> add     "run_tests(permutations_alt)"
    "def permutations_alt(str1, str2):\n",
      "    for char in string:\n",
      "        dict_chars[char] += 1\n",
      "    return dict_chars\n",
      "\n",
    "def permutations_alt(str1, str2):\n",
      "    if len(str1) != len(str2):\n",
      "        return False\n",
      "    unique_counts1 = unique_counts(str1)\n",
      "    unique_counts2 = unique_counts(str2)\n",
      "    return unique_counts1 == unique_counts2\n",
keep keep keep keep replace keep keep keep keep keep
 Updated unit test to use nose and moved it to Test Case section. 
arrays-strings/permutation.ipynb