John Fouhy wrote:
2009/3/31 james carnell <jimcarn...@yahoo.com>:
for row in range(25,31,1):
for col in range(10,12, 0.3): #<- Crash Bang doesn't work 0.3 = zero =
infinite loop?
[...]
is there no way to do it with a range function (and have it still look like
you're not on crack)?
Well, you could do this:
[float(x)/3 for x in range(30, 37)]
[10.0, 10.333333333333334, 10.666666666666666, 11.0,
11.333333333333334, 11.666666666666666, 12.0]
Or even:
[math.floor(10*float(x)/3)/10 for x in range(30, 37)]
[10.0, 10.300000000000001, 10.6, 11.0, 11.300000000000001, 11.6, 12.0]
However, the builtin range() only works with integers. I think there
is a range() function in the python cookbook that will do fractional
step sizes.
But really, there's nothing wrong with your while loop.
You could boil your own range function (beware: binary floating point
may be imprecise)
def frange(start, stop, step):
width = stop - start
n = round(width / step)
return [start + step*i for i in xrange(n)]
or returning generator instead (may be preferable if the size of the
list is extremely large):
def frange(start, stop, step):
width = stop - start
n = round(width / step)
return (start + step*i for i in xrange(n))
slightly obscured version:
def frange(start, stop, step):
return (start + step*i for i in range(round((stop - start) / step)))
more complex homebrew frange may return a class that really emulates
xrange, by implementing __getitem__, iterator protocol, generator
protocol, and all the sugar without ever creating a real list.
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