现在的位置: 主页 > 公司荣誉 > 文章列表

python中的tuple不是immutable (tuple in python is n

作者:昆明飞华工贸有限公司 来源:www.kmfhgm.com    未知发布时间:2017-09-15 10:27:39
python中的tuple不是immutable (tuple in python is not immutable)

There are lots of article to say that tuple in pyton in immutable, but after my test, this is not true.


Please see the example:

Python 2.7.2 (default, Jun 12 2011, 15:08:59) [MSC v.1500 32 bit (Intel)] on win32
>>> L = [1,2,3]

# define a typle
>>> dd = tuple(L)

# print all methods of tuple
>>> print dir(dd)
['__add__', '__class__', '__contains__', '__delattr__', '__doc__', '__eq__', '__
format__', '__ge__', '__getattribute__', '__getitem__', '__getnewargs__', '__get
slice__', '__gt__', '__hash__', '__init__', '__iter__', '__le__', '__len__', '__
lt__', '__mul__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__'
, '__rmul__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', 'count
', 'index']
>>> print dd
(1, 2, 3)
>>> dd.__add__("a")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: can only concatenate tuple (not "str") to tuple

# Note, tuple is changed.
>>> dd.__add__(dd)
(1, 2, 3, 1, 2, 3)
>>>


,专题,站群系统

企业建站2800元起,携手武汉肥猫科技,做一个有见地的颜值派!更多优惠请戳:武汉网站建设 http://www.45qun.com

上一篇:.net事务(1、SqlTransaction) 下一篇:最后一页