MergeSort implemented and added to the data structures and algorithms section.

DataStructuresAndAlgorithms/Algorithms/python/MergeSort.py

@@ -0,0 +1,50 @@
+# Python program for implementation of Merge Sort
+
+def mergeSort(arr):
+    if len(arr) > 1:
+
+        # Finding the mid of the array
+        mid = len(arr) // 2
+
+        # Dividing the array elements
+        L = arr[:mid]   # into 2 halves
+        R = arr[mid:]
+
+        # Sorting the first half
+        mergeSort(L)
+
+        # Sorting the second half
+        mergeSort(R)
+
+        i = j = k = 0
+
+        # Copy data to temp arrays L[] and R[]
+        while i < len(L) and j < len(R):
+            if L[i] < R[j]:
+                arr[k] = L[i]
+                i += 1
+            else:
+                arr[k] = R[j]
+                j += 1
+            k += 1
+
+        # Checking if any element was left
+        while i < len(L):
+            arr[k] = L[i]
+            i += 1
+            k += 1
+
+        while j < len(R):
+            arr[k] = R[j]
+            j += 1
+            k += 1
+
+
+# Driver code to test above
+arr = [64, 34, 25, 12, 22, 11, 90]
+
+mergeSort(arr)
+
+print("Sorted array is:")
+for i in range(len(arr)):
+    print("%d" % arr[i])