如何教Python“变量” [英] How to Teach Python "Variables"
问题描述
你好，
IIRC，我曾经看过Python没有变量的解释。在
感觉，比方说，C，而且从名称绑定到
对象。有没有人有链接？
谢谢，
Ami
Hello,
IIRC, I once saw an explanation how Python doesn''t have "variables" in
the sense that, say, C does, and instead has bindings from names to
objects. Does anyone have a link?
Thanks,
Ami
推荐答案
noneaécrit：
none a écrit :
你好，
IIRC，我曾经看过Python如何解释''在某些意义上，C表示变量
，而是将名称绑定到
对象。有没有人有链接？
谢谢，
Ami
Hello,
IIRC, I once saw an explanation how Python doesn''t have "variables"
in the sense that, say, C does, and instead has bindings from names to
objects. Does anyone have a link?
Thanks,
Ami
那个这是我经常听到的东西，我不知道。不知怎的，我不知道
了解C变量是如何不像python绑定的（差异是因为C变量是静态类型的并且完全消失在
运行时间;这些差异是否足够重要以保证这样的转移
术语？（是的还有一些其他的差异，但是然后问了
的问题在教育学的背景下，观众被引入基础知识。）
我的意思是：不是C变量也从名称绑定到对象？或者什么？
That''s something I''ve often heard and I don''t get it. Somehow I don''t
understand how C variables are not like python bindings (the differences
being that C variables are statically typed and completely disappear at
run-time; are these differences important enough to warrant such a shift
in terminology ? (yes there are some other differences, but then the
question is asked in a context of pedagogy, where the audience is
introduced to the basics))
I mean : aren''t C variables also bindings from names to objects ? Or what ?
AurélienCampéasschrieb：
Aurélien Campéas schrieb:
noneaécrit：
none a écrit :
>您好，
IIRC，我曾经看过Python没有变量的解释。在某种意义上说，比方说，C确实存在，而是从名称到对象具有绑定。有没有人有链接？
谢谢，
Ami
> Hello,
IIRC, I once saw an explanation how Python doesn''t have
"variables" in the sense that, say, C does, and instead has bindings
from names to objects. Does anyone have a link?
Thanks,
Ami
那是我的东西经常听到，我不明白。不知怎的，我不知道
了解C变量是如何不像python绑定的（差异是因为C变量是静态类型的并且完全消失在
运行时间;这些差异是否足够重要以保证这样的转移
术语？（是的还有一些其他的差异，但是然后问了
的问题在教育学的背景下，观众被引入基础知识。）
我的意思是：不是C变量也从名称绑定到对象？或者是什么 ？
That''s something I''ve often heard and I don''t get it. Somehow I don''t
understand how C variables are not like python bindings (the differences
being that C variables are statically typed and completely disappear at
run-time; are these differences important enough to warrant such a shift
in terminology ? (yes there are some other differences, but then the
question is asked in a context of pedagogy, where the audience is
introduced to the basics))
I mean : aren''t C variables also bindings from names to objects ? Or what ?
存在重大差异。在C中，你的名字指向
物理内存位置 - 固定位置，即。
因此你可以做到例如
some_struct a，b;
a = b = some_struct_value;
a.bar = 10;
b.bar = 20;
现在a.bar与b.bar不同
这与python完全不同语义，其中
a = b = some_object
a.bar = 10
b.bar = 20
将导致两次操作相同的对象。
所以python变量更像是C中的指针。
Diez
There are cruicial differences. In C, you have names pointing to
physical memory locations - fixed locations, that is.
Thus you can do e.g.
some_struct a, b;
a = b = some_struct_value;
a.bar = 10;
b.bar = 20;
Now a.bar will be different from b.bar
This is totally different from python semantics, where
a = b = some_object
a.bar = 10
b.bar = 20
will result in both times the same object being manipulated.
So python variables are more equivalent to pointers in C.
Diez
AurélienCampéas写道：
Aurélien Campéas wrote:
noneaécrit：
none a écrit :
>您好，
IIRC，我曾经看过Python没有变量的解释。在某种意义上说，比方说，C确实存在，而是从名称到对象具有绑定。有没有人有链接？
谢谢，
Ami
> Hello,
IIRC, I once saw an explanation how Python doesn''t have
"variables" in the sense that, say, C does, and instead has bindings
from names to objects. Does anyone have a link?
Thanks,
Ami
那是我的东西经常听到，我不明白。不知怎的，我不知道
了解C变量是如何不像python绑定的（差异是因为C变量是静态类型的并且完全消失在
运行时间;这些差异是否足够重要以保证这样的转移
术语？（是的还有一些其他的差异，但是然后问了
的问题在教育学的背景下，观众被引入基础知识。）
我的意思是：不是C变量也从名称绑定到对象？或者是什么 ？
That''s something I''ve often heard and I don''t get it. Somehow I don''t
understand how C variables are not like python bindings (the differences
being that C variables are statically typed and completely disappear at
run-time; are these differences important enough to warrant such a shift
in terminology ? (yes there are some other differences, but then the
question is asked in a context of pedagogy, where the audience is
introduced to the basics))
I mean : aren''t C variables also bindings from names to objects ? Or what ?
谢谢。
很可能你是对的 - 我不知道。然而，似乎有一些
的差异。举几个例子：
1.无论你是否在
中存储东西，都存在一个C变量。对于python变量而言，情况并非如此。 - 所以对于独立存在的东西来说，它更像是一个
名称。
2.当超出范围时，C变量（或C ++对象）完全消失，
但是对于Python对象来说并不一定如此。
3. C ++引用的语义如果a = b，你写的是ac =
3，然后是bc == 3.在Python中也是如此。但是如果a = b，并且
然后你写b = 5，那么a仍然绑定到b的原始值，
所以它不完全是喜欢参考。
4.等等
一方面，你显然是对的，也许没有空间
用于范式转换。 OTOH，如果最简单的解释是它就像一个
C / C ++变量/引用/指针除了1,2,3,4 ......，那么可能
它是不同的。我只是不知道，因此我的问题。
Thanks.
It''s very possible you''re right - I don''t know. There seem to be some
differences however. To name a few:
1. A C variable exists regardless of whether you''re storing something in
it. Not so for a python "variable" - so it''s a bit really more like a
name for something that exists independently.
2. C variables (or C++ objects) completely disappear when out of scope,
but that''s not necessarily true of Python objects.
3. C++ references have the semantics that if a = b, and you write a.c =
3, then b.c == 3. This is also true in Python. But then if a = b, and
then you write b = 5, then a is still bound to the original value of b,
so it''s not exactly like a reference.
4. Etc.
So on the one hand, you''re obviously right, and maybe there''s no room
for a paradigm shift. OTOH, if the simplest explanation is "it''s like a
C/C++ variable/reference/pointer except for 1, 2, 3, 4,...", then maybe
it is different. I just don''t know, hence my question.
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