def _truncate_float(matchobj, format_str='<STR_LIT>'):
if matchobj.group(<NUM_LIT:0>):<EOL><INDENT>return format(float(matchobj.group(<NUM_LIT:0>)), format_str)<EOL><DEDENT>return '<STR_LIT>'<EOL>
Truncate long floats

    Args:
        matchobj (re.Match): contains original float
        format_str (str): format specifier
    Returns:
       str: returns truncated float