operator module functions

Chris Angelico rosuav at gmail.com
Wed Oct 8 11:32:11 CEST 2014

(You didn't include any context in your post. Please quote as much
text as would be helpful; it's the easiest way to show what you're
talking about.)

On Wed, Oct 8, 2014 at 7:46 PM,  <marco.nawijn at colosso.nl> wrote:
> For me it makes sense. operator.add should be used in a "global" context
> (I don't know how to express it otherwise). So you provide it with the
> two values that you want to add. The .__add__ variants are bound to a
> particular instance and you provide it with a single value that you want
> to add.

What Steven's talking about is this:

>>> operator.add is operator.__add__

It's the exact same function, just accessed with a different name.

> As an example, you cannot use the dunder versions for literals.
>>> 2.__add__(3) # Oops, does not work
>>> a = 2
>>> a.__add__(3)
> 5

That's actually just a syntactic issue with integers and the dot. It
works fine if you use any other form of literal, or if you put a space
between the digits and the dot, or use parentheses, or anything; this
is the case with all methods off integers, not just dunder ones.

>>> 2 .__add__(3)
>>> (2).__add__(3)
>>> 2.0.__add__(3.0)

The object is exactly the same whether you reference the literal '2'
or the name 'a' that you've bound to it, so its methods must by
definition all be there.


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