Little Q: how to print a variable's name, not its value?

[Ron_Adam]

On Tue, 29 Mar 2005 11:23:45 -0500, Bill Mill <bill.mill at gmail.com>
wrote:

>On Tue, 29 Mar 2005 14:34:39 GMT, Ron_Adam <radam2 at tampabay.rr.com> wrote:
>> On 28 Mar 2005 23:01:34 -0800, "Dan Bishop" <danb_83 at yahoo.com> wrote:
>> 
>> >>>> def print_vars(vars_dict=None):
>> >...    if vars_dict is None:
>> >...       vars_dict = globals()
>> >...    for var, value in vars_dict.items():
>> >...       print '%s = %r' % (var, value)
>> >...
>> >>>> myPlace = 'right here'
>> >>>> myTime = 'right now'
>> >>>> print_vars()
>> >print_vars = <function print_vars at 0x401e0d84>
>> >__builtins__ = <module '__builtin__' (built-in)>
>> >myTime = 'right now'
>> >myPlace = 'right here'
>> >__name__ = '__main__'
>> >__doc__ = None
>> 
>> Fred = 5
>> John = 8
>> Winner = John
>> 
>> Both John and Winner are pointing to the literal '8'.
>
>ummm, yes, of course they are. What's your point?

Hi Bill,  

My point is if you look up the name and print it, you may get.

Instead of:

    Fred has 5 points
    John has 8 points

You could get:
 
    Fred has 5 points
    Winner has 8 points

Or something else depending on how many references you made to the
value 8.
 
>> Mixing data and program code, ie.. variable names as data, is not a
>> good idea.
>
>Down with eval! Exile exec! A pox on both their houses!
>
>(i.e. I respectfully disagree that mixing data with program code is a bad idea)

(I respectfully acknowledged your opinion.)

To be fair, it's not always bad.  But in most cases it is better not
too. 

I wasn't referring to using exec or eval, but to directly using data
values in the program code. 

Here's an example of mixing data and code. If I write a program that
checks a list for specific names and prints corresponding value for
each.

I would not do this:  ( Lots of stuff wrong with this example! )
    
    playerlist = ['John','Bob','Fred']
    John = 6
    Bob = 8
    Fred = 0

    for name in playerlist:
        if item == 'John':
            print 'John', John
        if item == 'Bob':
            print 'Bob', Bob

This is only good for one set of data, and each time my data changes,
I would need to rewrite the program code also.  This has data as
program code in both the variables and in the comparisons. 

Not mixing data and code:

    playerlist = {'John':6, 'Bob':8, 'Fred',0}
    players = ['John', 'Bob']

    for name in players:
        print name, playerlist[name]

This does the same thing as above, but data and program code are not
mixed. It's much easier to maintain and reuse.

Ron


>Peace
>Bill Mill
>bill.mill at gmail.com