Variables

[Richard Blackwood]

Kent Johnson wrote:

> Richard Blackwood wrote:
>
>>>> To All:
>>>>
>>>>    Folks, I need your help. I have a friend who claims that if I 
>>>> write:
>>>>
>>>> foo = 5
>>>>
>>>> then foo is NOT a variable, necessarily. 
>>>
>>>
>> Indeed, this language is math. My friend says that foo is a constant 
>> and necessarily not a variable. 
>
>
> Well, we mostly talk Python here, not math. In Python, if you say
> foo = 5
> foo is a name bound to an immutable value.
>
> If I had written foo = raw_input(), he would
>
>> say that foo is a variable. 
>
>
> That's funny. foo is still a name bound to an immutable (string) 
> value. foo is no more or less variable than it was with foo = 5.
>
> Which is perfectly fine except that he
>
>> insists that since programming came from math, the concept of 
>> variable is necessarily the identical. This can not be true. For 
>> example, I may define foo as being a dictionary, but I can not do 
>> this within math because there is no concept of dictionaries within 
>> mathematics; yet foo is a variable, a name bound to a value which can 
>> change.
>
>
> Sounds like you are having a stupid and meaningless argument with your 
> friend. What you call foo won't change what it is. He should learn 
> Python, then he would understand the true zen of foo.

That is exactly how I feel about it. Foo is what it is. Variable, name 
bound to immutable value, etc., what we call it doesn't really change 
how I program, only how I communicate with other programmers (and 
mathematicians). Is the notion of variable not a fundamental concept in 
programming?  Surely there must be an unambiguous definition I can relay 
to him.