defindent(text,prefix,predicate=None):"""Adds 'prefix' to the beginning of selected lines in 'text'.    If 'predicate' is provided, 'prefix' will only be added to the lines    where 'predicate(line)' is True. If 'predicate' is not provided,    it will default to adding 'prefix' to all non-empty lines that do not    consist solely of whitespace characters.    """ifpredicateisNone:defpredicate(line):returnline.strip()defprefixed_lines():forlineintext.splitlines(True):yield (prefix+lineifpredicate(line)elseline)return''.join(prefixed_lines())