PEP238 and zope

[Christian Tanzer]

barry at zope.com (Barry A. Warsaw) wrote:

> >>>>> "CT" == Christian Tanzer <tanzer at swing.co.at> writes:
> 
>     CT> This isn't portable behavior. According to the python library
>     CT> reference, `int` may round on some platforms.
> 
> It also says:
> 
>     "This is ugly -- the language definition should require truncation
>     towards zero."

Not in my book (2.1 of April 15, 2001). But that sentence is a good
addition.

> Okay so
> 
>     int(math.floor(a / b))
> 
> or
> 
>     divmod(a, b)[0]
> 
> are better.  Either way, wrap it in a function called "div()" and use
> that where ever you absolutely must have integer division.

Unfortunately, I just learned that they were better even if `int`
behaved portably:

    >>> divmod (5.,-2.)
    (-3.0, -1.0)
    >>> int(5.0/-2.0)
    -2
    >>> int(math.floor(5.0/-2.0))
    -3

> really-portable-code-is-always-ugly-anyway-ly y'rs,

So-lets-make-it-even-uglier-?-ly y'rs, 

-- 
Christian Tanzer                                         tanzer at swing.co.at
Glasauergasse 32                                       Tel: +43 1 876 62 36
A-1130 Vienna, Austria                                 Fax: +43 1 877 66 92