[Tutor] how to identify a list element is in the range of a tuple element or a list element
kent37 at tds.net
Thu Nov 17 15:53:10 CET 2005
Srinivas Iyyer wrote:
> Dear group,
> I have a list of numbers:
> a = [10,3,4.6,2.3,4.8,10.8,4.1]
> b = ['1-4','4.1-8','8.1-12','12.1-16']
> c = ((1,4),(4.1,8),(8.1-12),(12.1,16))
> Now I want to find if elements of list a are in the
> range of list b and in the range of tuple b.
> I know (and my limited knowledge on range function) is
> not allowing me to think of a new way.
> Could any one please help me.
> I wish to have the answer as:
> 10 8.1-12
> 3 1-4
A brute-force approach is straighforward. I ignore b since it has the same values as c, and I corrected the third entry in c to be a tuple.
>>> a = [10,3,4.6,2.3,4.8,10.8,4.1]
>>> c = ((1,4),(4.1,8),(8.1, 12),(12.1,16))
>>> for x in a:
... for lower, upper in c:
... if lower <= x <= upper:
... print '%-5s%s-%s' % (x, lower, upper)
If a and c are large this could be slow, it could be optimized by searching in c instead of exhaustive search, or by terminating the inner loop when a match is found or when lower > x.
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