1.27 += 不等同于=+ ================== .. image:: http://image.iswbm.com/20200804124133.png 对列表 进行\ ``+=`` 操作相当于 extend,而使用 ``=+`` 操作是新增了一个列表。 因此会有如下两者的差异。 .. code:: python # =+ >>> a = [1, 2, 3, 4] >>> b = a >>> a = a + [5, 6, 7, 8] >>> a [1, 2, 3, 4, 5, 6, 7, 8] >>> b [1, 2, 3, 4] # += >>> a = [1, 2, 3, 4] >>> b = a >>> a += [5, 6, 7, 8] >>> a [1, 2, 3, 4, 5, 6, 7, 8] >>> b [1, 2, 3, 4, 5, 6, 7, 8]