相关疑难解决方法(0)

>>> b = []
>>> c = '1234'
>>> b += c
>>> b
['1', '2', '3', '4']
>>> 

这里发生了什么？这应该不行,对吗？还是我错过了一些明显的东西？

>>> b = []
>>> c = '1234'
>>> b + c
Traceback (most recent call last):
  File "<pyshell#7>", line 1, in <module>
    b + c
TypeError: can only concatenate list (not "str") to list
>>> 

然后a += b 并不总是等同于a = a + b？