CODEWITHSUNDEEP
pythonjsonlistdictionary
Krishna Manohar
Krishna Manohar

Reputation: 334

How to create a dictionary with duplicate keys and form a list of dictionary

I am trying to write a program where I am having a list of dictionaries in the following manner

[
  {
    'unique':1,
    'duplicate':2,
  },
  {
    'unique':1,
    'duplicate':2,
  },
  {
    'unique':1,
    'duplicate':2,
  },
  {
    'unique':1,
    'duplicate':2,
  }
]

Can we form it as a dictionary, where the first key in tuple should become unique Key in a dictionary and it's corresponding values as a list for that values

Example:

[
  {
   'unique':1,
   'duplicate':2,
  }, 
 {
  'unique':1,
  'duplicate':8,
 },
 {
  'unique':2,
  'duplicate':2,
 },
 {
  'unique':1,
  'duplicate':4,
 }
]

The above list should be converted into the following
---- Expected Outcome ---
[
  {
   'unique':1,
   'duplicates':[2,8,4]
  },
  {
   'unique':2,
   'duplicates':[2]
  }
]

PS: I am doing this in python

Thanks for the code in advance

Upvotes: 2

Views: 936

Answers (5)

kederrac
kederrac

Reputation: 17322

you can also use itertools.groupby:

from itertools import groupby
from operator import itemgetter

l = [
  {
   'unique':1,
   'duplicate':2,
  }, 
 {
  'unique':1,
  'duplicate':8,
 },
 {
  'unique':2,
  'duplicate':2,
 },
 {
  'unique':1,
  'duplicate':4,
 }
]

key = itemgetter('unique')
result = [{'unique':k, 'duplicate': list(map(itemgetter('duplicate'), g))}
          for k, g in groupby(sorted(l, key=key ), key = key)]
print(result)

output:

[{'unique': 1, 'duplicate': [2, 8, 4]}, {'unique': 2, 'duplicate': [2]}]

Upvotes: 1

Mehul Gupta
Mehul Gupta

Reputation: 1939

unique=[]
duplicate ={}
for items in data:
   if items['unique'] not in unique:
       unique.append(items['unique'])
       duplicate[items['unique']]=[items['duplicate']]
   else:
       duplicate[items['unique']].append(items['duplicate'])

new_data=[]
for key in unique:
    new_data.append({'unique':key,'duplicate':duplicate[key]})

Explanation: In the first for loop, I am appending unique keys to 'unique'. If the key doesn't exists in 'unique', I will append it in 'unique' & add a key in 'duplicate' with value as single element list. If the same key is found again, I simply append that value to 'duplicate' corresponding the key. In the 2nd loop, I am creating a 'new_dict' where I am adding these unique keys & its duplicate value list

Upvotes: 0

Lipen
Lipen

Reputation: 85

defaultdict(list) may help you here:

from collections import defaultdict

# data = [ {'unique': 1, 'duplicate': 2}, ... ]  # your data
dups = defaultdict(list) # {unique: [duplicate]}

for dd in data:
    dups[dd['unique']].append(dd['duplicate'])

answer = [dict(unique = k, duplicates = v) for k, v in dups.items()]

If you don't know the name of unique key, then replace 'unique' with something like

unique_key = list(data[0].keys())[0]

Upvotes: 0

Chayan Bansal
Chayan Bansal

Reputation: 2085

This might help you:

l = [
  {
   'unique':1,
   'duplicate':2,
  }, 
 {
  'unique':1,
  'duplicate':8,
 },
 {
  'unique':2,
  'duplicate':2,
 },
 {
  'unique':1,
  'duplicate':4,
 }
]

a = set()
for i in l:
    a.add(i['unique'])
d = {i:[] for i in a }
for i in l:
    d[i['unique']].append(i['duplicate'])
output = [{'unique': i, 'duplicate': j}for i, j in d.items()]

The output will be:

[{'unique': 1, 'duplicate': [2, 8, 4]}, {'unique': 2, 'duplicate': [2]}]

Upvotes: 0

Leafar
Leafar

Reputation: 374

I think this list comprehension can solve your problem:

result = [{'unique': id, 'duplicates': [d['duplicate'] for d in l if d['unique'] == id]} for id in set(map(lambda d: d['unique'], l))]

Upvotes: 0

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