python: add problem 49 and test function

Author: supercoderhawk

Python/solution_41_50.py

@@ -0,0 +1,31 @@
+# -*- coding: UTF-8 -*-
+
+class Solution_41_50:
+    def groupAnagrams(self, strs):
+        """
+        Given an array of strings, group anagrams together.
+
+        For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"],
+        Return:
+
+        [
+          ["ate", "eat","tea"],
+          ["nat","tan"],
+          ["bat"]
+        ]
+        :type strs: List[str]
+        :rtype: List[List[str]]
+        """
+        word_maps = {}
+        if len(strs) <= 1:
+            return [strs]
+
+        word_maps[str(sorted(strs[0]))] = [strs[0]]
+        for s in strs[1:]:
+            sign = str(sorted(s))
+            if sign not in word_maps:
+                word_maps[sign] = [s]
+            else:
+                word_maps[sign].append(s)
+
+        return word_maps.values()

Python/test_solution_41_50.py

@@ -0,0 +1,13 @@
+from unittest import TestCase
+from solution_41_50 import Solution_41_50
+
+# -*- coding: UTF-8 -*-
+class TestSolution_41_50(TestCase):
+  def setUp(self):
+    self.sln = Solution_41_50()
+
+  def test_groupAnagrams(self):
+    a = ["eat", "tea", "tan", "ate", "nat", "bat"]
+    b = [['eat', 'tea', 'ate'], ['tan', 'nat'], ['bat']]
+    self.assertEqual(self.sln.groupAnagrams(a),b)
+    self.assertEqual(self.sln.groupAnagrams(['']), [['']])