import re


def add_indent(text, indent, re_start = re.compile(r'\n(?=.)')):        # re.compile(r'(?m)^(?=.)')
    """
    Append `indent` string at the beginning of each line of `text` excluding the 1st line (!).
    Empty lines (containing zero characters, not even a space) are left untouched!
    """
    if not indent: return text
    return re_start.sub('\n' + indent, text)
    # if not text: return text
    # return indent + text.replace('\n', '\n' + indent)