Re: [Tutor] Sorting Dictionary of Dictionary by certain Value
Thanks to Kent Johnson, Robert Berman, Bill Campbell and John Fouhy for
the replies.
They have been useful.
Kent Johnson wrote:
On Tue, Sep 23, 2008 at 8:41 PM, Joe Python [EMAIL PROTECTED] wrote:
Hi Pythonistas,
I have a large dictionary of dictionary (50,000+ keys) which has a structure
as follows:
DoD = {
'flintstones' : {
'husband' : "fred",
'pal' : "barney",
'income': 500,
},
'jetsons' : {
'husband' : "george",
'wife' : "jane",
'his boy' : "elroy",
'income': 700,
},
'simpsons' : {
'husband' : "homer",
'wife' : "marge",
'kid' : "bart",
'income': 600,
},
};
I want to sort the dictionary by 'income'
Is there an efficient way to do the same.
As has been pointed out, you can't sort a dictionary, it is unordered.
You can sort the list of key, value pairs. The simplest way is to make
a key function that extracts the value on which to sort.
The key, value pairs will look like ('flintstones', {
'husband' : "fred",
'pal' : "barney",
'income': 500,
)
You want to sort on the 'income' element of the value; this key
function will work:
def key(item):
return item[1]['income']
Then sort with
sorted(DoD.iteritems(), key=key)
Kent
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Re: [Tutor] Sorting Dictionary of Dictionary by certain Value
-Original Message-
Hi Pythonistas,
I have a large dictionary of dictionary (50,000+ keys) which
has a structure as follows:
DoD = {
'flintstones' : {
'husband' : fred,
'pal' : barney,
'income': 500,
},
'jetsons' : {
'husband' : george,
'wife' : jane,
'his boy' : elroy,
'income': 700,
},
'simpsons' : {
'husband' : homer,
'wife' : marge,
'kid' : bart,
'income': 600,
},
};
I want to sort the dictionary by 'income'
Is there an efficient way to do the same.
Thanks in advance.
- Jo
This sounds like it'd be a good job for a database...perhaps SQLite?
Mike
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Re: [Tutor] Sorting Dictionary of Dictionary by certain Value
2008/9/24 Joe Python [EMAIL PROTECTED]: Hi Pythonistas, I have a large dictionary of dictionary (50,000+ keys) which has a structure as follows: [snip] I want to sort the dictionary by 'income' Is there an efficient way to do the same. Note that you cannot sort a dictionary. The best you can do is build a list containing the dictionary keys in the appropriate order and use the dictionary in combination with that list. You could try this: 1. Build a dictionary mapping income to list of families. 2. Sort keys to this dictionary. 3. Iterate through this sorted list, emitting family names. e.g. from collections import defaultdict familiesByIncome = defaultdict(list) for family in DoD: familiesByIncome[DoD[family]['income']].append(family) incomes = familiesByIncome.keys() incomes.sort() # sorts from lowest to highest familiesSorted = [] for inc in incomes: familiesSorted.extend(familiesByIncome[inc]) ## HTH! -- John. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Sorting Dictionary of Dictionary by certain Value
On Wed, Sep 24, 2008, John Fouhy wrote:
2008/9/24 Joe Python [EMAIL PROTECTED]:
Hi Pythonistas,
I have a large dictionary of dictionary (50,000+ keys) which has a structure
as follows:
[snip]
I want to sort the dictionary by 'income'
Is there an efficient way to do the same.
Note that you cannot sort a dictionary. The best you can do is build
a list containing the dictionary keys in the appropriate order and use
the dictionary in combination with that list.
What you can do is create a class for the objects in the top
level dictionary, and create a __cmp__ method in that class using
cmp to compare the objects in the dictionary, finally sorting the
values.
class MyStuff(object):
def __init__(self, name, income):
self.name = name
self.income = int(income)
def cmp(self, other):
return(cmp((-self.income, self.name), -other.income, other.name))
d = dict(
key1 = MyStuff('john', 1),
key2 = MyStuff('bill', 2),
)
vals = d.values()
vals.sort()
# vals should be sorted by income in descending order and name.
Bill
--
INTERNET: [EMAIL PROTECTED] Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/ PO Box 820; 6641 E. Mercer Way
Voice: (206) 236-1676 Mercer Island, WA 98040-0820
Fax:(206) 232-9186
People who relieve others of their money with guns are called robbers. It
does not alter the immorality of the act when the income transfer is
carried out by government.
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Re: [Tutor] Sorting Dictionary of Dictionary by certain Value
On Tue, Sep 23, 2008, Bill Campbell wrote:
On Wed, Sep 24, 2008, John Fouhy wrote:
2008/9/24 Joe Python [EMAIL PROTECTED]:
Hi Pythonistas,
I have a large dictionary of dictionary (50,000+ keys) which has a structure
as follows:
[snip]
I want to sort the dictionary by 'income'
Is there an efficient way to do the same.
Note that you cannot sort a dictionary. The best you can do is build
a list containing the dictionary keys in the appropriate order and use
the dictionary in combination with that list.
What you can do is create a class for the objects in the top
level dictionary, and create a __cmp__ method in that class using
cmp to compare the objects in the dictionary, finally sorting the
values.
class MyStuff(object):
def __init__(self, name, income):
self.name = name
self.income = int(income)
Whoops
The method below should be def __cmp__
def cmp(self, other):
return(cmp((-self.income, self.name), -other.income, other.name))
d = dict(
key1 = MyStuff('john', 1),
key2 = MyStuff('bill', 2),
)
vals = d.values()
vals.sort()
# vals should be sorted by income in descending order and name.
Bill
--
INTERNET: [EMAIL PROTECTED] Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/ PO Box 820; 6641 E. Mercer Way
Voice: (206) 236-1676 Mercer Island, WA 98040-0820
Fax:(206) 232-9186
People who relieve others of their money with guns are called robbers. It
does not alter the immorality of the act when the income transfer is
carried out by government.
___
Tutor maillist - Tutor@python.org
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--
Bill
--
INTERNET: [EMAIL PROTECTED] Bill Campbell; Celestial Software LLC
URL: http://www.celestial.com/ PO Box 820; 6641 E. Mercer Way
Voice: (206) 236-1676 Mercer Island, WA 98040-0820
Fax:(206) 232-9186
Microsoft is to computers what Phillip Morris is to lungs.
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Re: [Tutor] Sorting Dictionary of Dictionary by certain Value
This might help you.
http://blog.modp.com/2008/09/sorting-python-dictionary-by-value-take.html
Robert
Joe Python wrote:
Hi Pythonistas,
I have a large dictionary of dictionary (50,000+ keys) which has a
structure as follows:
DoD = {
'flintstones' : {
'husband' : "fred",
'pal' : "barney",
'income' : 500,
},
'jetsons' : {
'husband' : "george",
'wife' : "jane",
'his boy' : "elroy",
'income' : 700,
},
'simpsons' : {
'husband' : "homer",
'wife' : "marge",
'kid' : "bart",
'income' : 600,
},
};
I want to sort the dictionary by 'income'
Is there an efficient way to do the same.
Thanks in advance.
- Jo
___
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___
Tutor maillist - Tutor@python.org
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Re: [Tutor] Sorting Dictionary of Dictionary by certain Value
On Tue, Sep 23, 2008 at 8:41 PM, Joe Python [EMAIL PROTECTED] wrote:
Hi Pythonistas,
I have a large dictionary of dictionary (50,000+ keys) which has a structure
as follows:
DoD = {
'flintstones' : {
'husband' : fred,
'pal' : barney,
'income': 500,
},
'jetsons' : {
'husband' : george,
'wife' : jane,
'his boy' : elroy,
'income': 700,
},
'simpsons' : {
'husband' : homer,
'wife' : marge,
'kid' : bart,
'income': 600,
},
};
I want to sort the dictionary by 'income'
Is there an efficient way to do the same.
As has been pointed out, you can't sort a dictionary, it is unordered.
You can sort the list of key, value pairs. The simplest way is to make
a key function that extracts the value on which to sort.
The key, value pairs will look like ('flintstones', {
'husband' : fred,
'pal' : barney,
'income': 500,
)
You want to sort on the 'income' element of the value; this key
function will work:
def key(item):
return item[1]['income']
Then sort with
sorted(DoD.iteritems(), key=key)
Kent
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