merge_sort.py

def mergeSort(nlist):
    print("Splitting ",nlist)
    if len(nlist)>1:
        mid = len(nlist)//2
        lefthalf = nlist[:mid]
        righthalf = nlist[mid:]

        mergeSort(lefthalf)
        mergeSort(righthalf)
        i=j=k=0       
        while i < len(lefthalf) and j < len(righthalf):
            if lefthalf[i] < righthalf[j]:
                nlist[k]=lefthalf[i]
                i=i+1
            else:
                nlist[k]=righthalf[j]
                j=j+1
            k=k+1
        #for remaining elements in lefthalf(if any)
        while i < len(lefthalf):
            nlist[k]=lefthalf[i]
            i=i+1
            k=k+1
        ##for remaining elements in righthalf(if any)
        while j < len(righthalf):
            nlist[k]=righthalf[j]
            j=j+1
            k=k+1
    print("Merging ",nlist)

print("Unsorted Input -- ,end='')
nlist = list(map(int, input().split()))
mergeSort(nlist)
print("Sorted Output -- , end='')
print(nlist)