I got it! How to force a single number to be a tuple

[Jeff Sandys]

y=2,
The comma makes tuples.
y=2, 3.0, 4.5,
also works.

Are you sure that you want a list of numbers as an immutable tuple?
Tuples are intended for hetrogenious sequences like a data record,
(like y=2, 3.0, 4.5 is a record of say quantity, price and weight, 
and y=3.0, 2, 4.5 is a completely different thing).
Tuples can be used as an index in a dictionary.

A list is mutable, intended for a homogenious sequence, the elements 
can be changed and a list can not be used a dictionary index.
(like y=[2, 3.0, 4.5] is a list of the weights of three items and 
y=[3.0, 2, 4.5] has the same meaning)

Thanks,
Jeff Sandys

Jinming Xu wrote:
> 
> Sorry for the previous message. It's really a simple question and I have
> solved it myself.
> 
> Thanks,
> 
> Jinming
> 
> ------------------------------------------------------------------------
> Hi Folks,
> 
> I have a number sequence, which is put into a tuple like this:
> 
> y=2, 3.0, 4.5
> 
> I can manipulate the sequence as a tuple when it has more than 1 number. But
> when the sequence has only 1 number, like
> 
> y=2
> 
> I have trouble to manipulate it as a tuple.  I guess there must be a way to
> forece a single number to be a tuple. Could anyone please tell me that?
> 
> Thanks,
> 
> Jinming