[Tutor] finding numbers in range of of numbers

[Srinivas Iyyer]

Dear Alan and tutors,

I apologize for careless description of my problem that lead to confusion. 
the problem arises due to large range of numbers and range has direction (both ascending and descending). 

I am giving an example from my real problem.

What I want to do:
 I want to check if a[.][1] and a[.][2] are 'within the range' of any element of b[.][1] or b[.][2]. (here '.' means any sub-element of list b.

a[.][1] and a[.][2] or b[.][1] b[.][2] can be either ascending or descending order
Ascending example from list a and b:
'xa','1511255', '1511279'
'xb','7516599','7516623'
'G1','1511200','1511325'
'G2','7516500','7516625'

descending order from list a and b:
'xc','98356290','98356266'
'G3','98356335','98356126'

a = [['xa','1511255', '1511279'],['xb','7516599','7516623'],['xc','98356290','98356266']]

b = [['G1','1511200','1511325'],['G2','7516500','7516625'],['G3','98356335','98356126']]

>>> for item1 in a:
...     i1st = int(item1[1])
...     i1en = int(item1[2])
...     for item2 in b:
...             i21 = int(item2[1])
...             i22 = int(item2[2])
...             if i1st and i1en in xrange(i21,i22):
...                     print "\t".join(item1)+'\t'+"\t".join(item2)
...             if i1st and i1en in xrange(i22,i21):
...                     print "\t".join(item1)+'\t'+"\t".join(item2)
...
xa      1511255 1511279 G1      1511200 1511325
xb      7516599 7516623 G2      7516500 7516625
xc      98356290        98356266        G3      98356335        98356126



Issue 1:  
a. Range of numbers is too high and xrange is also too slow.
   I used xrange instead of range - a slow process

Issue 2: 
Is this is a correct way to tackle this kind of problem. 


Issue 3: 
I have 200K elements in a anb b lists. this code has been running for last 18 hours and only 800 elements of 200K have been evaluated. 

Could tutors help me with 3 issues. 
Thank you. 


srini


--- On Tue, 10/21/08, Alan Gauld <alan.gauld at btinternet.com> wrote:

> From: Alan Gauld <alan.gauld at btinternet.com>
> Subject: Re: [Tutor] finding numbers in range of of numbers
> To: tutor at python.org
> Date: Tuesday, October 21, 2008, 5:10 AM
> "Srinivas Iyyer" <srini_iyyer_bio at yahoo.com>
> wrote
> 
> > [[10,45],[14,23],[39,73],[92,135]]
> >
> > I want to identify if any of the items in this list
> are in range of 
> > [5,100]
> 
> Sorry, I have no idea what you mean by that. Can you give
> an example of passing and failing tests?
> 
> For example do any/all of the elements in your sample
> list pass the test? If so why?
> 
> Often if you think carefullly and specifically about your
> requirement the solution will become apparent. And if
> you don't you are open to ambiguity and confusion.
> 
> -- 
> Alan Gauld
> Author of the Learn to Program web site
> http://www.freenetpages.co.uk/hp/alan.gauld 
> 
> 
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