Dinesh B Vadhia wrote:
I'm suffering from brain failure (or most likely just being brain
less!) and need help to create a list comprehension for this problem:
d is a list of integers: d = [0, 8, 4, 4, 4, 7, 2, 5, 1, 1, 5, 11, 11,
1, 6, 3, 5, 6, 11, 1]
Want to create a new list that adds the
On 7/3/2009 4:19 PM Emile van Sebille said...
On 7/3/2009 3:54 PM Dinesh B Vadhia said...
As the lists of integers get larger (mine are in the thousands of
integers per list) the list comprehension solution will get slower.
Do you agree?
Yes, no doubt. Your original post asked only if the
On 7/3/2009 3:54 PM Dinesh B Vadhia said...
Thanks Emile / Kent.
The problem I see with this solution is that at each stage it is
re-summing the j's instead of retaining a running total which the
'for-loop' method does ie.
>>> dd = []
>>> y = d[0]
>>> for i, x in enumerate(d):
>>>
"Dinesh B Vadhia" wrote
As the lists of integers get larger ... the list comprehension
solution will get slower. Do you agree?
Yes thats why Chris said the linear loop solution is almost
certainly faster in this case. However you could speed up
the for loop significantly by missing out th
y += x
>>>dd.append(y)
As the lists of integers get larger (mine are in the thousands of integers per
list) the list comprehension solution will get slower. Do you agree?
Dinesh
From: Kent Johnson
Sent: Friday, July 03, 2009 1:21 PM
To: Dinesh B Vadhia
Cc: tutor@python.o
On 7/3/2009 1:59 PM Chris Fuller said...
The problem with these list comprehensions is that they have O(n**2)
complexity.
But, the more you work with them the more ease you'll develop at
understanding and deploying them. I often find that a (quick) (perhaps
complex) list comprehension is
On Friday 03 July 2009 15:37, Emile van Sebille wrote:
> On 7/3/2009 1:21 PM Kent Johnson said...
>
> > On Fri, Jul 3, 2009 at 3:49 PM, Dinesh B
> >
> > Vadhia wrote:
> >> d = [0, 8, 4, 4, 4, 7, 2, 5, 1, 1, 5, 11, 11, 1, 6, 3, 5, 6, 11, 1]
> >>
> >> and we want:
> >>
> >> [0, 8, 12, 16, 20, 27, 29,
On 7/3/2009 1:21 PM Kent Johnson said...
On Fri, Jul 3, 2009 at 3:49 PM, Dinesh B
Vadhia wrote:
d = [0, 8, 4, 4, 4, 7, 2, 5, 1, 1, 5, 11, 11, 1, 6, 3, 5, 6, 11, 1]
and we want:
[0, 8, 12, 16, 20, 27, 29, 34, 35, 36, 41, 52, 63, 64, 70, 73, 78, 84, 95,
96]
dd = [ sum(d[:j]) for j in range(len(d
On Fri, Jul 3, 2009 at 3:49 PM, Dinesh B
Vadhia wrote:
> d = [0, 8, 4, 4, 4, 7, 2, 5, 1, 1, 5, 11, 11, 1, 6, 3, 5, 6, 11, 1]
>
> and we want:
>
> [0, 8, 12, 16, 20, 27, 29, 34, 35, 36, 41, 52, 63, 64, 70, 73, 78, 84, 95,
> 96]
> dd = [ sum(d[:j]) for j in range(len(d)) ][1:]
>
> gives:
>
> [0, 8, 1
]
Dinesh
Message: 6
Date: Fri, 03 Jul 2009 12:22:30 -0700
From: Emile van Sebille
To: tutor@python.org
Subject: Re: [Tutor] list comprehension problem
Message-ID:
Content-Type: text/plain; charset=ISO-8859-1; format
On 7/3/2009 12:09 PM Dinesh B Vadhia said...
I'm suffering from brain failure (or most likely just being brain less!)
and need help to create a list comprehension for this problem:
d is a list of integers: d = [0, 8, 4, 4, 4, 7, 2, 5, 1, 1, 5, 11, 11,
1, 6, 3, 5, 6, 11, 1]
Want to create a n
I'm suffering from brain failure (or most likely just being brain less!) and
need help to create a list comprehension for this problem:
d is a list of integers: d = [0, 8, 4, 4, 4, 7, 2, 5, 1, 1, 5, 11, 11, 1, 6, 3,
5, 6, 11, 1]
Want to create a new list that adds the current number and the pri
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