def check_for_tab(lines):
    index = [(i + 1) for (i, s) in enumerate(lines) if ('\t' in s)]
    if (len(index) > 0):
        return index
    else:
        return ''
def check_for_tab(lines):
    index = [(i + 1) for (i, s) in enumerate(lines) if ('\t' in s)]
    if (len(index) > 0):
        return index
    else:
        return 