[Tutor] method to print in interpreter

[Remco Gerlich]

On  0, Christopher Smith <csmith@blakeschool.org> wrote:
> Dear List,
> 
> I read about defining __str__ in a class so the interpreter will know how 
> to process a print command but I have not yet found what I must do to be 
> able to get it to print if, in the interpreter, you don't use a "print" 
> command.  i.e. How can I get the evaluation itself to print instead of 
> giving the address of the instance.  Here's a run to demonstrate what I 
> mean.
> 
> >>> from my import point
> >>> p=point(1,2)
> >>> print p
> (1,2)
> >>> p
> <my.point instance at 0x00c448b0>
> >>> 
> 
> I would like ">>> p" to return something like '(1,2)', too.

This uses the repr() of the object, not its str(). You need to define
__repr__().

> Also, in the Runtime Services section of the library documentation, I 
> see "cpickle" and "operator" listed and I find "test_cpickle.py" and 
> "test_operator.py" on my disk, but I don't see the "cpickle.py" or 
> "operator.py" anywhere.  Where are they?

They're written in C, not Python (that's what the c in CPickle means, it's
the faster equivalent of the Pickle module).

See Modules/cPickle.c and Modules/operator.c in the source distribution.

cPickle is nice C code, but operator.c is ugly, apparently just wrappers
around other interpreter functions.

-- 
Remco Gerlich