En Fri, 05 Feb 2010 19:22:39 -0300, bartc <ba...@freeuk.com> escribió:
"Steve Holden" <st...@holdenweb.com> wrote in message
news:mailman.1998.1265399766.28905.python-l...@python.org...
Arnaud Delobelle wrote:
Robert Kern <robert.k...@gmail.com> writes:
I prefer Guido's formulation (which, naturally, I can't find a direct
quote for right now): if you expect that a boolean argument is only
going to take *literal* True or False, then it should be split into
^^^^^^^^^^^^^^^^^^^^^^^
two functions.
So rather than three boolean arguments, would you have eight functions?
If there's genuinely a need for that functionality, yes.
So you want a function such as drawtext(s, bold=true, italic=false,
underline=true) to be split into:
drawtext(s)
drawtextb(s)
drawtexti(s)
drawtextu(s)
drawtextbi(s)
drawtextbu(s)
drawtextiu(s)
drawtextbiu(s)
Note the *literal* part. If you (the programmer) is likely to know the
parameter value when writing the code, then the function is actually two
separate functions.
By example, foo.get_path(absolute=True) should be written as
foo.get_absolute_path() and foo.get_relative_path()
It gets worse when one parameter alters the type of the returned value, or
even the number of returned values. This is an actual example:
def build_image(self, zone=-1, return_sizes=False):
...
if return_size:
return img, sizes
else:
return img
image = foo.build_image(3)
but:
image, sizes = foo.build_image(3, True)
It should be split onto two separate functions; in this particular case,
computing 'sizes' required actually drawing the image, so the solution was
to make those 'sizes' attributes of the returned image.
--
Gabriel Genellina
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