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Seymore4Head Seymore4Head at Hotmail.invalid
Mon Sep 15 17:28:07 CEST 2014


On Mon, 15 Sep 2014 09:05:50 -0400 (EDT), Dave Angel
<davea at davea.name> wrote:

>Seymore4Head <Seymore4Head at Hotmail.invalid> Wrote in message:
>> import random
>> nums=range(1,11)
>> print (nums)
>> samp=random.sample(nums,10)
>> top=nums
>> newlist=nums[::-1]
>> tail=newlist
>> 
>> for x in range(10):
>>     print ("Top {:2d}    Tail {:2.0f}  Sample {:2d}
>> ".format(top[x],tail[x],samp[x]))
>>     
>> I don't understand why the command nums=range(1,11) doesn't work.
>> I would think that print(nums) should be 1,2,3 ect.
>> Instead it prints range(1,11)
>
>You need to specify that you're using python 3.x
>
>In python 2, nums would indeed be a list. And range (5000000)
> would be a list of 5 million items, taking quite a while and lots
> of memory to build.  So python 3 uses lazy evaluation when it
> can. In this case it returns a range sequence type,  not a
> list.
>
>https://docs.python.org/3/library/stdtypes.html#typesseq-range
>
>If you need the ints all at once, simply call list.
>    nums =list (range (1, 11)
>
>> 
>> Why does random.sample(nums,10) give me the numbers between 1 and 10.
>> I am missing something subtle again.
>> 
>> 
>
>It doesn't give you the numbers between 1 and 10,  it gives you a
> list composed of those numbers in an arbitrary order, but with no
> duplicates. 
>
>Your question is incomplete.  It does that because it's defined
> to.  But clearly you're puzzled.  So what is confusing? The fact
> that there are 10? The fact that they're between 1 and 10
> inclusive? Or the fact there are no duplicates?  Or something
> else?
>
>You might help your confusion by experimenting.  Try 7 instead of
> 10. Or pick different range limits. 

Actually I do understand that random.sample(nums,10) does give a
sample of the numbers in the list.  What was throwing me off was that
nums=range(1,11) did not appear to be a list ,but sample was still
treating it as a list.

But I also figured out what I really needed to do was
nums=list(range(1,11)

Thanks everyone.



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