looping through a list of lists.

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saoirse_79

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Oct 8, 2003, 11:04:28 AM10/8/03
to
I have a list of lists as follows:
[['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'],
['-', '-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'],
['T', 'L', 'E', 'E', 'L', 'M', 'K', 'L', 'S', 'P', 'E']]
I want to be able to read each character and compare it with all
characters at the same positon in all sublists. Is this possible.
I have tried a few different methods but nothing seems to allow me to
compare the sublists character by character.


SBru...@trisystems.co.uk

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Oct 8, 2003, 11:13:24 AM10/8/03
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> From: saoirse_79 [SMTP:saoir...@yahoo.com]
PythonWin 2.3.2 (#49, Oct 2 2003, 20:02:00) [MSC v.1200 32 bit (Intel)] on
win32.
Portions Copyright 1994-2001 Mark Hammond (mham...@skippinet.com.au) - see
'Help/About PythonWin' for further copyright information.
>>> spam = [['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'],['-',

'-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'], ['T', 'L', 'E', 'E', 'L',
'M', 'K', 'L', 'S', 'P', 'E']]
>>> for eggs, chips, beans in zip(*spam):
... print eggs, chips, beans
...
- - T
- - L
- - E
- - E
- L L
- Q M
- Q K
K T L
S N S
A S P
K E E

HTH...

Cheers,
Simon Brunning,
http://www.brunningonline.net/simon/blog/
--LongSig


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Rob Hunter

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Oct 8, 2003, 12:13:08 PM10/8/03
to
The responder to this post has a cool way of doing it, but it won't
work (I believe) if you have an arbitrary number of sublists. Can you
clarify the problem? Do you have an arbitrary number of sublists? Or
is it always 3?

Rob

On Wednesday, October 8, 2003, at 11:04 AM, saoirse_79 wrote:

> I have a list of lists as follows:
> [['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'],
> ['-', '-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'],
> ['T', 'L', 'E', 'E', 'L', 'M', 'K', 'L', 'S', 'P', 'E']]
> I want to be able to read each character and compare it with all
> characters at the same positon in all sublists. Is this possible.
> I have tried a few different methods but nothing seems to allow me to
> compare the sublists character by character.
>
>
>
>

> --
> http://mail.python.org/mailman/listinfo/python-list
>


Andy Todd

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Oct 8, 2003, 12:29:57 PM10/8/03
to
SBru...@trisystems.co.uk wrote:
>>From: saoirse_79 [SMTP:saoir...@yahoo.com]

>>I have a list of lists as follows:
>>[['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'],
>>['-', '-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'],
>>['T', 'L', 'E', 'E', 'L', 'M', 'K', 'L', 'S', 'P', 'E']]
>>I want to be able to read each character and compare it with all
>>characters at the same positon in all sublists. Is this possible.
>>I have tried a few different methods but nothing seems to allow me to
>>compare the sublists character by character.
>
>
> PythonWin 2.3.2 (#49, Oct 2 2003, 20:02:00) [MSC v.1200 32 bit (Intel)] on
> win32.
> Portions Copyright 1994-2001 Mark Hammond (mham...@skippinet.com.au) - see
> 'Help/About PythonWin' for further copyright information.
>
>>>>spam = [['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'],['-',

>
> '-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'], ['T', 'L', 'E', 'E', 'L',
> 'M', 'K', 'L', 'S', 'P', 'E']]
>
>>>>for eggs, chips, beans in zip(*spam):
>
> ... print eggs, chips, beans
> ...
> - - T
> - - L
> - - E
> - - E
> - L L
> - Q M
> - Q K
> K T L
> S N S
> A S P
> K E E
>
> HTH...
>
> Cheers,
> Simon Brunning,
> http://www.brunningonline.net/simon/blog/
> --LongSig
>

OK Simon, that is pretty evil. Please explain to a poor ignoramous the
difference between zip(spam) and zip(*spam).

I can see that the first gives;

[(['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'],),
(['-','-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'],),
(['T', 'L', 'E', 'E', 'L','M', 'K', 'L', 'S', 'P', 'E'],)]

and the second produces the result you illustrate above, but why?

Regards,
Andy
--
--------------------------------------------------------------------------------
From the desk of Andrew J Todd esq - http://www.halfcooked.com/

Peter Otten

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Oct 8, 2003, 1:15:44 PM10/8/03
to
Rob Hunter wrote:

> The responder to this post has a cool way of doing it, but it won't
> work (I believe) if you have an arbitrary number of sublists. Can you
> clarify the problem? Do you have an arbitrary number of sublists? Or
> is it always 3?

I you are referring to the zip trick posted by SBru...@trisystems.co.uk,
it *does work for an arbitrary number of sublists, but not for
arbitrary-length sublists:

>>> for loc in zip(*"alpha beta gamma delta".split()):
... print loc
...
('a', 'b', 'g', 'd')
('l', 'e', 'a', 'e')
('p', 't', 'm', 'l')
('h', 'a', 'm', 't')
>>>

Peter

anton muhin

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Oct 8, 2003, 1:31:13 PM10/8/03
to
Peter Otten wrote:

Consider the following:

PythonWin 2.2.2 (#37, Nov 26 2002, 10:24:37) [MSC 32 bit (Intel)] on win32.


Portions Copyright 1994-2001 Mark Hammond (mham...@skippinet.com.au) -
see 'Help/About PythonWin' for further copyright information.

>>> l = [range(0, 5), range(1, 7), range(3, 5)]
>>> l
[[0, 1, 2, 3, 4], [1, 2, 3, 4, 5, 6], [3, 4]]
>>> for e in zip(*l):
... print e
...
(0, 1, 3)
(1, 2, 4)
>>> for e in map(None, *l): print e
...
(0, 1, 3)
(1, 2, 4)
(2, 3, None)
(3, 4, None)
(4, 5, None)
(None, 6, None)
>>>

It pads missing elements with Nones. Is it what you need?

zip(*l) is similar to zip(l[0], l[1], ...., l[len(l) - 1])---it
substitutes list elements to function parameters.

HTH,
anton.

Rob Hunter

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Oct 8, 2003, 1:42:00 PM10/8/03
to
Oh. That's pretty cool actually.

Rob

> --
> http://mail.python.org/mailman/listinfo/python-list
>


SBru...@trisystems.co.uk

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Oct 13, 2003, 8:17:22 AM10/13/03
to r...@cs.brown.edu, saoir...@yahoo.com, pytho...@python.org
> On Wednesday, October 8, 2003, at 11:04 AM, saoirse_79 wrote:

> I have a list of lists as follows:
> [['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'],
> ['-', '-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'],
> ['T', 'L', 'E', 'E', 'L', 'M', 'K', 'L', 'S', 'P', 'E']]
> I want to be able to read each character and compare it with all
> characters at the same positon in all sublists. Is this possible.
> I have tried a few different methods but nothing seems to allow me
to
> compare the sublists character by character.

> From: Rob Hunter [SMTP:r...@cs.brown.edu]
>
> The responder to this post has a cool way of doing it, but it won't
> work (I believe) if you have an arbitrary number of sublists. Can you
> clarify the problem? Do you have an arbitrary number of sublists? Or
> is it always 3?

It *can* work for arbitrary numbers of sublists, depending upon what one
means by 'comparing'. For example:

>>> spam = [['-', '-', '-', '-', '-', '-', '-', 'K', 'S', 'A', 'K'], ['-',
'-', '-', '-', 'L', 'Q', 'Q', 'T', 'N', 'S', 'E'], ['T', 'L', 'E', 'E', 'L',
'M', 'K', 'L', 'S', 'P', 'E']]

>>> for sublist in zip(*spam):
... print sublist, max(sublist), min(sublist)
...
('-', '-', 'T') T -
('-', '-', 'L') L -
('-', '-', 'E') E -
('-', '-', 'E') E -
('-', 'L', 'L') L -
('-', 'Q', 'M') Q -
('-', 'Q', 'K') Q -
('K', 'T', 'L') T K
('S', 'N', 'S') S N
('A', 'S', 'P') S A
('K', 'E', 'E') K E
>>> spam.append(['1', '@', '_', 'Z', 'A', 'z', 'a', 'T', 'L', '5', '!'])
>>> for sublist in zip(*spam):
... print sublist, max(sublist), min(sublist)
...
('-', '-', 'T', '1') T -
('-', '-', 'L', '@') L -
('-', '-', 'E', '_') _ -
('-', '-', 'E', 'Z') Z -
('-', 'L', 'L', 'A') L -
('-', 'Q', 'M', 'z') z -
('-', 'Q', 'K', 'a') a -
('K', 'T', 'L', 'T') T K
('S', 'N', 'S', 'L') S L
('A', 'S', 'P', '5') S 5
('K', 'E', 'E', '!') K !

Cheers,
Simon Brunning,
http://www.brunningonline.net/simon/blog/
--LongSig

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