class_docstr: Demo where each line is executed as a separate block.
  
  The input script should be valid Python code.
  
  This class doesn't require any markup at all, and it's meant for simple
  scripts (with no nesting or any kind of indentation) which consist of
  multiple lines of input to be executed, one at a time, as if they had been
  typed in the interactive prompt.
  
  Note: the input can not have *any* indentation, which means that only
  single-lines of input are accepted, not even function definitions are
  valid.
docstr: Reload source from disk and initialize state.
docstr_tok: ["Reload","source","from","disk","and","initialize","state","."]
code: def reload(self):
      """Reload source from disk and initialize state."""
      # read data and parse into blocks
      self.fload()
      lines = self.fobj.readlines()
      src_b = [l for l in lines if l.strip()]
      nblocks = len(src_b)
      self.src = "".join(lines)
      self._silent = [False] * nblocks
      self._auto = [True] * nblocks
      self.auto_all = True
      self.nblocks = nblocks
      self.src_blocks = src_b
  
      # also build syntax-highlighted source
      self.src_blocks_colored = list(
          map(self.highlight, self.src_blocks)
      )
  
      # ensure clean namespace and seek offset
      self.reset()
  
imports: import os
  import re
  import shlex
  import sys
  import pygments
  from pathlib import Path
  from IPython.utils.text import marquee
  from IPython.utils import openpy
  from IPython.utils import py3compat
label_desc: Use image node_id 1 for calling the LineDemo obj's underlying member method code with example usage: obj.reload() without return types