code: def t_IDENTIFIER(t):
    r"[A-Z_a-z][0-9A-Z_a-z]*"
    if t.value in keywords:
      t.type = t.value
    return f t_IDENTIFIER(t):
    r"[A-Z_a-z][0-9A-Z_a-z]*"
    if t.value in keywords:
      t.type = t.value
    return t
docs: r"[A-Z_a-z][0-9A-Z_a-z]*