How to uniqufy the tuple element?
i have a result tuple of dictionaries.
result = ({'name': 'xxx', 'score': 120L }, {'name': 'xxx', 'score': 100L}, {'name': 'yyy', 'score': 10L})
I want to uniqify it. After uniqify operation result = ({'name': 'xxx', 'score': 120L }, {'name': 'yyy', 'score': 10L})
The result
contain only one dictionary
of each na开发者_开发百科me
and the dict
should have maximum score
. The final result should be in the same format ie tuple of dictionary.
from operator import itemgetter
names = set(d['name'] for d in result)
uniq = []
for name in names:
scores = [res for res in result if res['name'] == name]
uniq.append(max(scores, key=itemgetter('score')))
I'm sure there is a shorter solution, but you won't be able to avoid filtering the scores by name in some way first, then find the maximum for each name.
Storing scores in a dictionary with names as keys would definitely be preferable here.
I would create an intermediate dictionary mapping each name to the maximum score for that name, then turn it back to a tuple of dicts afterwards:
>>> result = ({'name': 'xxx', 'score': 120L }, {'name': 'xxx', 'score': 100L}, {'name': 'xxx', 'score': 10L}, {'name':'yyy', 'score':20})
>>> from collections import defaultdict
>>> max_scores = defaultdict(int)
>>> for d in result:
... max_scores[d['name']] = max(d['score'], max_scores[d['name']])
...
>>> max_scores
defaultdict(<type 'int'>, {'xxx': 120L, 'yyy': 20})
>>> tuple({name: score} for (name, score) in max_scores.iteritems())
({'xxx': 120L}, {'yyy': 20})
Notes:
1) I have added {'name': 'yyy', 'score': 20}
to your example data to show it working with a tuple with more than one name.
2)I use a defaultdict that assumes the minimum value for score is zero. If the score can be negative you will need to change the int parameter of defaultdict(int) to a function that returns a number smaller than the minimum possible score.
Incidentally I suspect that having a tuple of dictionaries is not the best data structure for what you want to do. Have you considered alternatives, such as having a single dict, perhaps with a list of scores for each name?
I would reconsider the data structure to fit your needs better (for example dict hashed with name with list of scores as value), but I would do like this:
import operator as op
import itertools as it
result = ({'name': 'xxx', 'score': 120L },
{'name': 'xxx', 'score': 100L},
{'name': 'xxx', 'score': 10L},
{'name':'yyy', 'score':20})
# groupby
highscores = tuple(max(namegroup, key=op.itemgetter('score'))
for name,namegroup in it.groupby(result,
key=op.itemgetter('name'))
)
print highscores
How about...
inp = ({'name': 'xxx', 'score': 120L }, {'name': 'xxx', 'score': 100L}, {'name': 'yyy', 'score': 10L})
temp = {}
for dct in inp:
if dct['score'] > temp.get(dct['name']): temp[dct['name']] = dct['score']
result = tuple({'name': name, 'score': score} for name, score in temp.iteritems())
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