anything like C++ references?

[Erik Max Francis]

Tom Plunket wrote:

> Is there any way to do references like this in Python?  It'd be
> like this, though clearly this doesn't change the thing I want it
> to change:

Hi, Tom.

There's no builtin support for this in Python, but you can do it
yourself easily enough.  Pass in a mutable container, and then twiddle
the object you want inside it.

>>> def change(val):
...  val[0] += 1
... 
>>> v = [0]
>>> change(v)
>>> v
[1]

I'm a strong believer in writing self-documenting code, so in a case
like this I write a (trivial) class that makes my intent crystal clear:

>>> class Container:
...  def __init__(self, value=None): self.value = value
...  def get(self): return self.value
... 
>>> class Container:
...  def __init__(self, value=None): self.value = value
...  def get(self): return self.value
...  def set(self, value): self.value = value
... 
>>> def change(container): 
...  container.set(container.get() + 1)
... 
>>> 
>>> c = Container(0)
>>> change(c)
>>> c.get()
1

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