recursion of ESC

recursion_demo.py

#change to Python 3.x and fixed a bug

import types

cursor = '\t'

def recur(arr, cursorList, result):
    if arr == []:
        return (result , cursorList)
    head = arr[0]
    if type(head) is list:
        (r,c) = recur(head, [], [])
        return recur(arr[1:], cursorList, result + [r]+ c )
    else:
        if head == cursor:
            return recur(arr[1:], cursorList + [head], result)
        else:
            return recur(arr[1:], cursorList, result + [head])

def helper (arr):
    (r,c) = recur (arr,[],[])
    return r+c

if __name__ == "__main__":

    arr = ['3', '555', ['4', '\t']]
    print (helper(arr))
    # output:   ['3', '555', ['4'], '\t']

    arr = ['35', '65', ['4', ['\t', '45', ['5']]]]
    print (helper(arr))
    # output:   ['35', '65', ['4', ['45', ['5']], '\t']]

    arr = ['35', '65', ['4', ['\t', '45', ['5']]], '24']
    print (helper(arr))