recursion of ESC

recursion_demo.py

import types

cursor = '\t'
def recursion (arr):
  copy = []
  # 循环列表每个元素然后一个个附着到 copy 里面最后返回的
  for item in arr:
    if type (item) is types.ListType:
      # 如果子列表存在 cursor 就把它提出放到列表同一级的后面一个位置, 否则原样递归
      if cursor in item:
        item.remove (cursor)
        if len (item) > 0:
          copy.append (item)
        copy.append (cursor)
      else:
        copy.append (recursion (item))
    else:
      # 如果字符串中存在 cursor 就提出来放到字符串后边作为一个函数, 否则原样
      if item.find (cursor) < 0:
        copy.append (item)
      else:
        copy.append (item.replace (cursor, ''))
        copy.append (cursor)
  return copy

arr = ['3' , '5\t']
print (recursion (arr))
# output:   ['3', '5', '\t']

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

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