compare list

[Ben Bush]

what does the following code mean?
 if item in list2:
if item + 1 in list1 and item + 1 in list2:


 On 11/14/05, Brian van den Broek <broek at cc.umanitoba.ca> wrote:
>
> Ben Bush said unto the world upon 2005-11-14 05:51:
> > I have four lists:
> > lisA=[1,2,3,4,5,6,9]
> > lisB=[1,6,5]
> > lisC=[5,6,3]
> > lisD=[11,14,12,15]
> > how can I write a function to compare lisB, lisC and lisD with lisA, if
> they
> > share two continuous elements (the order does not matter), then return
> 1,
> > otherwise return 0. For example, lisA, lisB and lisC have 5,6 or 6,5 so
> > these comparison will return 1 but the comparison between lisD and lisA
> > return 0.
> > --
> > Thanks!
> > Ben Bush
>
> Hi Ben,
>
> the code below is tested no further than shown. And, I'm no expert --
> I imagine there are better ways. With luck, I'll learn them in a
> follow-up from someone more skilled :-)
>
> >>> def list_common_continuity_comp(list1, list2):
> for item in list1:
> if item in list2:
> if item + 1 in list1 and item + 1 in list2:
> return True
> return False
>
> >>> lisA=[1,2,3,4,5,6,9]
> >>> lisB=[1,6,5]
> >>> lisC=[5,6,3]
> >>> lisD=[11,14,12,15]
> >>> list_common_continuity_comp(lisA, lisB)
> True
> >>> list_common_continuity_comp(lisA, lisC)
> True
> >>> list_common_continuity_comp(lisA, lisD)
> False
> >>> list_common_continuity_comp(lisD, lisA)
> False
> >>> list_common_continuity_comp(lisA, lisA)
> True
> >>> list_common_continuity_comp(lisB, lisA)
> True
>
>
> That gets you a binary comparison. To make it a polyadic:
>
>
> >>> def multi_list_continuity_comp(list_of_lists):
> list1 = list_of_lists[0]
> for other_list in list_of_lists[1:]:
> if not list_common_continuity_comp(list1, other_list):
> return False
> return True
>
> >>> meta_list1 = [lisA, lisB, lisC, lisD]
> >>> meta_list2 = meta_list1[:-1]
> >>> multi_list_continuity_comp(meta_list1)
> False
> >>> multi_list_continuity_comp(meta_list2)
> True
> >>>
>
>
> Some edge cases haven't been handled:
>
> >>> multi_list_continuity_comp([])
>
> Traceback (most recent call last):
> File "<pyshell#101>", line 1, in -toplevel-
> multi_list_continuity_comp([])
> File "<pyshell#95>", line 2, in multi_list_continuity_comp
> list1 = list_of_lists[0]
> IndexError: list index out of range
> >>>
>
> but this should get you started.
>
> Best,
>
> Brian vdB
>
>


--
Thanks!
Ben Bush
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