code: def pad_leading_whitespace(string, zero_level, blist, options=None):
      
      opts = parse_options(options)
      if opts.compact:
          # if compact mode is on, split the string into two, trim the first
          # position and merge the two portions.
          trim_limit = find_trim_limit(string, opts)
          comment_line = re.search('^[ \t]*;', string, re.M)
          if comment_line and opts.indent_comments:
              trim_limit = comment_line.end()
          substr1 = string[0:trim_limit]
          substr2 = string[trim_limit:]
          substr1 = trim(substr1)
          string = substr1 + substr2
      else:
          # If in nocompact mode, remove leading spaces only
          string = re.sub('^[ \t]+', '', string, count=0)
  
      indent_level = zero_level
      if blist:
          indent_level = blist[-1]['indent_level']
  
      padding = ' ' * indent_level
      padding = tabify(padding, opts)
      return padding + string, indent_level
docs: pad_leading_whitespace(string : str, current_level : int,
                                 zero_level : int) -> str
  
      >>> pad_leading_whitespace("(print 'Yello)")
      "         (print 'Yello)"
  
      Takes a string and indents it using the current indentation level
      and the zero level.