Merge Sort in Python

merge_sort.py

def sort(arr):
    length = len(arr)
    
    if length >= 2:
        splitIndex = int(length / 2)
        
        left = arr[0:splitIndex]
        right = arr[splitIndex:length]
        
        left = sort(left)
        right = sort(right)
        
        output = []
        
        l = 0
        r = 0
        
        while l < len(left) or r < len(right):
            
            if r >= len(right):
                output.append(left[l])
                l += 1
                continue
            
            if l >= len(left):
                output.append(right[r])
                r += 1
                continue
            
            if left[l] < right[r]:
                output.append(left[l])
                l += 1
                continue
            
            else:
                output.append(right[r])
                r += 1
                continue
            
        return output
        
    else:
        return arr