Re: [Tutor] Grouping based on attributes of elements in a List
ranjan das wrote:
> I have the following list
>
> List=[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
> 'R9'),
> ('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
> ('G1',
> 'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5') ]
>
>
> now I want to group this elements of List first by index [1] that is (CFS
> and LOOSEFREIGHT ) together and for those elements which are grouped
> together for LOOSEFREIGHT, i want to further divide them into different
> groups based on index[2] that is (LCL or MIXEDLCL)
>
>
> So essentially i want them grouped into different lists and my solution
> should be of the form
>
> New_List=[ [ ( 'G1', 'CFS', 'FCL', 'R1' ), ('G1', 'CFS', 'FCL', 'R2' ),
> ('G4', 'CFS', 'FCL', 'R10' ) ], [ ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
> ('G2', 'LOOSEFREIGHT', 'LCL', 'R5' )], [ ('G3', 'LOOSEFREIGHT',
> 'MIXEDLCL', 'R9')] ]
>
> How do I do it?
>
> I managed to do divide them into different lists based on index [1]
> however
> I was not able to further divide them based on index [2]
>
> Any help is appreciated
Assuming you have a function
def group_list(items, key):
# ...
that takes a list and a function to extract the key you can apply that
recursively first on the initial list, then on all partial lists
def group_recursive(items, keys):
if not keys:
return items
firstkey = keys[0]
rest = keys[1:]
items = group_list(items, firstkey)
if rest:
return [group_recursive(item, rest) for item in items]
return items
if __name__ == "__main__":
from operator import itemgetter
import json
items = [
('G1', 'CFS', 'FCL', 'R1'),
('G3', 'LOOSEFREIGHT', 'MIXEDLCL', 'R9'),
('G4', 'CFS', 'FCL', 'R10'),
('G2', 'LOOSEFREIGHT', 'LCL', 'R4'),
('G1', 'CFS', 'FCL', 'R2' ),
('G2', 'LOOSEFREIGHT', 'LCL', 'R5')
]
groups = group_recursive(items, [itemgetter(1), itemgetter(2)])
print json.dumps(groups, indent=2)
One way to implement group_list() is to sort the items and then use
itertools.groupby() to create the sublists. Another is to put the items into
a dictionary with key(item) as the dict key and a list of items as the
value.
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Re: [Tutor] Grouping based on attributes of elements in a List
You are right, lambda lis: lis[1:3] would be more readable 2011/3/30 Sander Sweers > On 30 March 2011 00:30, Alan Gauld wrote: > > Wouldn't you just return a tuple of the two elements? > > > > Or am I missing something having jumped into the middle of the thread... > > Ah yes, you are correct. But imo reading "key=lambda l: (l[1], l[0], > l[2])" (which would be needed to sort how the OP wanted) hurts my eyes > ;-). Anyway, both options will work fine for the OP. > > Greets > Sander > ___ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > http://mail.python.org/mailman/listinfo/tutor > ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Grouping based on attributes of elements in a List
On 30 March 2011 00:30, Alan Gauld wrote: > Wouldn't you just return a tuple of the two elements? > > Or am I missing something having jumped into the middle of the thread... Ah yes, you are correct. But imo reading "key=lambda l: (l[1], l[0], l[2])" (which would be needed to sort how the OP wanted) hurts my eyes ;-). Anyway, both options will work fine for the OP. Greets Sander ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Grouping based on attributes of elements in a List
"Sander Sweers" wrote flexible, readable and elegant than using a lamda. How would you sort on the first and last item with lambda? Wouldn't you just return a tuple of the two elements? Or am I missing something having jumped into the middle of the thread... Alan G. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Grouping based on attributes of elements in a List
>From python docs:
For non-negative indices, the length of a slice is the difference of the
indices, if both are within bounds. For example, the length of word[1:3] is
2.
Example:
>>> list_[1][1:3]
('LOOSEFREIGHT', 'MIXEDLCL')
>>>
As I said i think my approach is more pythonic, but I'm not absolutely sure.
With such approach I don't need importing, I use slicing and you are right,
your approach is more flexible and would work on more cases, but in this
particular case I still think unnecessary. Maybe someone else could tell us
which is the best option.
El 30 de marzo de 2011 00:14, Sander Sweers escribió:
> 2011/3/29 Rafael Durán Castañeda :
> > And more pythonic, I think
>
> I don't agree :-). I think itemgetter from the operator module is more
> flexible, readable and elegant than using a lamda. How would you sort
> on the first and last item with lambda?
>
> Greets
> Sander
>
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Re: [Tutor] Grouping based on attributes of elements in a List
2011/3/29 Rafael Durán Castañeda : > And more pythonic, I think I don't agree :-). I think itemgetter from the operator module is more flexible, readable and elegant than using a lamda. How would you sort on the first and last item with lambda? Greets Sander ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Grouping based on attributes of elements in a List
On 29 March 2011 23:52, Sander Sweers wrote:
> On 29 March 2011 22:03, ranjan das wrote:
>> New_List=[ [ ( 'G1', 'CFS', 'FCL', 'R1' ), ('G1', 'CFS', 'FCL', 'R2' ),
>> ('G4', 'CFS', 'FCL', 'R10' ) ], [ ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
>> ('G2', 'LOOSEFREIGHT', 'LCL', 'R5' )], [ ('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
>> 'R9')] ]
Hmm, looking at your New_list you actually want to sort on 3
"indexes", on 1 then 0 then 2. So change the key= part from before to
key=operator.itemgetter(1,0,2) and it will match your New_list
perfectly.
Greets
Sander
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Re: [Tutor] Grouping based on attributes of elements in a List
This would work nice too:
list_=[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
'R9'), ('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
('G1', 'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5') ]
>>> sorted(list_,key=lambda l: l[1:3])
[('G1', 'CFS', 'FCL', 'R1'), ('G4', 'CFS', 'FCL', 'R10'), ('G1', 'CFS',
'FCL', 'R2'), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4'), ('G2', 'LOOSEFREIGHT',
'LCL', 'R5'), ('G3', 'LOOSEFREIGHT', 'MIXEDLCL', 'R9')]
>>>
And more pythonic, I think
2011/3/29 Sander Sweers
> On 29 March 2011 22:03, ranjan das wrote:
> > List=[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
> 'R9'),
> > ('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
> ('G1',
> > 'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5') ]
> >
> >
> > now I want to group this elements of List first by index [1] that is
> (CFS
> > and LOOSEFREIGHT ) together and for those elements which are grouped
> > together for LOOSEFREIGHT, i want to further divide them into different
> > groups based on index[2] that is (LCL or MIXEDLCL)
> >
> >
> > So essentially i want them grouped into different lists and my solution
> > should be of the form
> >
> > New_List=[ [ ( 'G1', 'CFS', 'FCL', 'R1' ), ('G1', 'CFS', 'FCL', 'R2' ),
> > ('G4', 'CFS', 'FCL', 'R10' ) ], [ ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
> > ('G2', 'LOOSEFREIGHT', 'LCL', 'R5' )], [ ('G3', 'LOOSEFREIGHT',
> 'MIXEDLCL',
> > 'R9')] ]
> >
> > How do I do it?
>
> You can use itemgetter from the operator module. The below should do
> what you want. I am using sorted to return a new list but you can also
> sort the list in place with list.sort().
>
> >>> import operator
> >>> l =[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
> 'R9'), ('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
> ('G1', 'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5') ]
> >>> sorted(l, key=operator.itemgetter(1,2))
> [('G1', 'CFS', 'FCL', 'R1'), ('G4', 'CFS', 'FCL', 'R10'), ('G1',
> 'CFS', 'FCL', 'R2'), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4'), ('G2',
> 'LOOSEFREIGHT', 'LCL', 'R5'), ('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
> 'R9')]
>
> Greets
> Sander
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Re: [Tutor] Grouping based on attributes of elements in a List
On 29 March 2011 22:03, ranjan das wrote:
> List=[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL', 'R9'),
> ('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ), ('G1',
> 'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5') ]
>
>
> now I want to group this elements of List first by index [1] that is (CFS
> and LOOSEFREIGHT ) together and for those elements which are grouped
> together for LOOSEFREIGHT, i want to further divide them into different
> groups based on index[2] that is (LCL or MIXEDLCL)
>
>
> So essentially i want them grouped into different lists and my solution
> should be of the form
>
> New_List=[ [ ( 'G1', 'CFS', 'FCL', 'R1' ), ('G1', 'CFS', 'FCL', 'R2' ),
> ('G4', 'CFS', 'FCL', 'R10' ) ], [ ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
> ('G2', 'LOOSEFREIGHT', 'LCL', 'R5' )], [ ('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
> 'R9')] ]
>
> How do I do it?
You can use itemgetter from the operator module. The below should do
what you want. I am using sorted to return a new list but you can also
sort the list in place with list.sort().
>>> import operator
>>> l =[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL', 'R9'),
>>> ('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ), ('G1',
>>> 'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5') ]
>>> sorted(l, key=operator.itemgetter(1,2))
[('G1', 'CFS', 'FCL', 'R1'), ('G4', 'CFS', 'FCL', 'R10'), ('G1',
'CFS', 'FCL', 'R2'), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4'), ('G2',
'LOOSEFREIGHT', 'LCL', 'R5'), ('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
'R9')]
Greets
Sander
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Re: [Tutor] Grouping based on attributes of elements in a List
On 3/29/2011 4:03 PM, ranjan das wrote:
I have the following list
List=[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
'R9'), ('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL',
'R4' ), ('G1', 'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL',
'R5') ]
now I want to group this elements of List first by index [1] that is
(CFS and LOOSEFREIGHT ) together and for those elements which are
grouped together for LOOSEFREIGHT, i want to further divide them into
different groups based on index[2] that is (LCL or MIXEDLCL)
So essentially i want them grouped into different lists and my
solution should be of the form
New_List=[ [ ( 'G1', 'CFS', 'FCL', 'R1' ), ('G1', 'CFS', 'FCL', 'R2'
), ('G4', 'CFS', 'FCL', 'R10' ) ], [ ('G2', 'LOOSEFREIGHT', 'LCL',
'R4' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5' )], [ ('G3',
'LOOSEFREIGHT', 'MIXEDLCL', 'R9')] ]
How do I do it?
I managed to do divide them into different lists based on index [1]
however I was not able to further divide them based on index [2]
Any help is appreciated
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You can you list comprehension (three times) checking for membership of
the relevant items, or you can use for loop to go over all available
tuples and sort them into different lists using if. In any case, after
that you create a list of the three required lists.
Eli
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[Tutor] Grouping based on attributes of elements in a List
I have the following list
List=[( 'G1', 'CFS', 'FCL', 'R1' ),('G3', 'LOOSEFREIGHT', 'MIXEDLCL', 'R9'),
('G4', 'CFS', 'FCL', 'R10' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ), ('G1',
'CFS', 'FCL', 'R2' ), ('G2', 'LOOSEFREIGHT', 'LCL', 'R5') ]
now I want to group this elements of List first by index [1] that is (CFS
and LOOSEFREIGHT ) together and for those elements which are grouped
together for LOOSEFREIGHT, i want to further divide them into different
groups based on index[2] that is (LCL or MIXEDLCL)
So essentially i want them grouped into different lists and my solution
should be of the form
New_List=[ [ ( 'G1', 'CFS', 'FCL', 'R1' ), ('G1', 'CFS', 'FCL', 'R2' ),
('G4', 'CFS', 'FCL', 'R10' ) ], [ ('G2', 'LOOSEFREIGHT', 'LCL', 'R4' ),
('G2', 'LOOSEFREIGHT', 'LCL', 'R5' )], [ ('G3', 'LOOSEFREIGHT', 'MIXEDLCL',
'R9')] ]
How do I do it?
I managed to do divide them into different lists based on index [1] however
I was not able to further divide them based on index [2]
Any help is appreciated
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