Is empty string cached?

[Steve Holden]

Farshid Lashkari wrote:
> When I pass an empty string to a function is a new string object created 
> or does python use some global pre-created object? I know python does 
> this with integer objects under a certain value. For instance, in the 
> following code is a new string object created for each function call?
> 
> func(0,'')
> func(1,'')
> func(2,'')
> func(3,'')
> 
> I tried the following commands in the interactive shell:
> 
>  >> x = ''
>  >> y = ''
>  >> x is y
> True
>  >> x = 'hello'
>  >> y = 'hello'
>  >> x is y
> True
> 
> This leads me to believe that python does reuse existing strings, but 
> once the variables are removed, does the item still exist in the cache?
> 
It takes far too little evidence to induce belief:

  >>> a = "hello"
  >>> b = "h"+"ello"
  >>> a is b
False
  >>> c = "hello"
  >>> b is a
False
  >>>

regards
  Steve
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