years later DeprecationWarning
Steven D'Aprano
steve at REMOVETHIScyber.com.au
Sun Mar 26 03:00:57 CEST 2006
On Wed, 22 Mar 2006 13:59:00 -0800, Chris Lasher wrote:
> Two things:
> 1) math.floor returns a float, not an int. Doing an int() conversion on
> a float already floors the value, anyways.
No it doesn't, or rather, int() is only equivalent to floor() if you limit
the input to non-negative numbers:
int(-2.2) => -2, but floor(-2.2) should give -3.
The standard definition of floor() and ceil() are:
floor(x) = maximum integer n such that n <= x
ceil(x) = minimum integer n such that n >= x
or as Python functions:
def floor(x):
"Returns the maximum integer less than or equal to x"
if x >= 0:
return int(x)
else:
if x % 1: return int(x)-1
else: return int(x)
def ceil(x):
"Returns the minimum integer greater than or equal to x"
return -floor(-x)
or even simpler:
from math import floor, ceil
(Caution: the functions defined in the math module return the floor and
ceiling as floats, not int, so you may want to wrap them in a call to int.)
--
Steven.
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