Swap values in dictionary which contain list of dictionaries?

Question

I have dictionary which contain list of dictionaries as below.

I want to swap all values of list of dictionary based on name.

Example: swap_function('Arvind','Jayesh') should swap other values like surname, fullname & email.

I have already tried a lot from other website's references but not able achieve my goal.

data = {
   "items":[
      {                 
         "name":"Arvind",
         "surname":"Patel",
         "fullname":"Arvind Patel",
         "email":"abc@xyx.com"        
      },
      {        
         "name":"Jayesh",
         "surname":"Patel",
         "fullname":"Jayesh Patel",
         "email":"Patel@gmail.com"
      },
      {        
         "name":"Krishna",
         "surname":"dave",
         "fullname":"Krishna dave",
         "email":"Krishna@xyz.com"
      },
      {        
         "name":"Aditya",
         "surname":"Patel",
         "fullname":"Aditya Patel",
         "email":"Aditya@abc.com"
      }

   ]
}

I have tried like below but after that I am out of ideas.

def name_swap(name1, name2):

   for key, item in data.items():
      first_dict = item[0]
      second_dict = item[1]
      third_dict = item[2]
      forth_dict = item[3]
      fifth_dict = item[4]

after name_swap('Arvind', 'Krishna')

output : 
data = {
   "items":[
      {                 
         "name":"Arvind",
         "surname":"dave",
         "fullname":"Krishna dave",
         "email":"Krishna@xyz.com"        
      },
      {        
         "name":"Jayesh",
         "surname":"Patel",
         "fullname":"Jayesh Patel",
         "email":"Patel@gmail.com"
      },
      {        
         "name":"Krishna",
         "surname":"Patel",
         "fullname":"Arvind Patel",
         "email":"abc@xyx.com"
      },
      {        
         "name":"Aditya",
         "surname":"Patel",
         "fullname":"Aditya Patel",
         "email":"Aditya@abc.com"
      }

   ]
}

Sorry I didn't get the question, can you show an example what happens if we swap "arvind" and "Jayesh" (first two) dictionaries. — sandeep, Sep 27 '19 at 06:01
So name will be same and other 3 values should be swapped? please confirm if I am right. — sandeep, Sep 27 '19 at 06:04
I´m not sure how big your data will be at the end but using first names as a "swapping parameter" can lead to multiple entries beeing swapped — mgruber, Sep 27 '19 at 06:06
It seems like you want to swap the position of the dictionaries in the list, is that correct? — Sayandip Dutta, Sep 27 '19 at 06:17

Massifox · Accepted Answer · 2019-09-27T07:37:02.447

Try this code:

i = next(i for i,item in enumerate(data['items']) if item['name'] == 'Arvind')
j = next(i for i,item in enumerate(data['items']) if item['name'] == 'Krishna')
data['items'][i]['name'], data['items'][j]['name'] = 'Krishna', 'Arvind'

And gives:

{'items': [{'name': 'Arvind',
   'surname': 'dave',
   'fullname': 'Krishna dave',
   'email': 'Krishna@xyz.com'},
  {'name': 'Jayesh',
   'surname': 'Patel',
   'fullname': 'Jayesh Patel',
   'email': 'Patel@gmail.com'},
  {'name': 'Krishna',
   'surname': 'Patel',
   'fullname': 'Arvind Patel',
   'email': 'abc@xyx.com'},
  {'name': 'Aditya',
   'surname': 'Patel',
   'fullname': 'Aditya Patel',
   'email': 'Aditya@abc.com'}]}

Ok now let's generalize this example, with the following function:

def swap_dict_list(dict_list, val1, val2, target='name', block_target=True):   
    try:
        i = next(i for i,item in enumerate(dict_list) if item[target] == val1)
        j = next(i for i,item in enumerate(dict_list) if item[target] == val2)
    except StopIteration:
        return dict_list
    dict_list[i], dict_list[j] = dict_list[j], dict_list[i]
    if block_target:
        dict_list[i][target], dict_list[j][target] = val1, val2
    return dict_list

In your case, you will use the function in this:

data['items'] = swap_dict_list(data['items'], 'Arvind', 'Krishna', target='name', block_target=True)

And you will get the same result shown above.

Code explenation

The swap_dict_list function receives as input the list of dictionaries 'dict_list', the 2 values to search ('val1' and 'val2') and the dictionary key on which to perform the target search.

The function finds the indexes corresponding to the two values searched for, and if they both exist it performs the swap. If block_target is True, the target values are not exchanged.

The search is effected efficiently using generator expression.

Thanks for your effort but still I am not getting expeceted output. above code switching position of dictionaries but I want to swap other values keeping name there. — Aditya, Sep 27 '19 at 06:58
add this line data['items'][i]['name'], data['items'][j]['name'] = 'Arvind', 'Jayesh' — Massifox, Sep 27 '19 at 07:04
as you can see in my queustion I have written that after name_swap('Arvind', 'Krishna') , I have kept expected output also I want exact output keeping same order of internal dictionaries. — Aditya, Sep 27 '19 at 07:29

TVK · Answer 2 · 2019-09-27T07:14:01.910

0

If i got you right:

First you want to find the indexes of the two dicts:

Find the index of a dict within a list, by matching the dict's value

then switch positions of the items:

How to switch position of two items in a Python list?

def switch(list,name1, name2):
     index1 = next((index for (index, d) in enumerate(list) if d["name"] == name1), None)
     index2 = next((index for (index, d) in enumerate(list) if d["name"] == name2), None)
     list[index1]['name'], list[index2]['name'] = list[index2]['name'], list[index1]['name']
     return list

data['items'] = switch(data['items'], 'Arvind', 'Krishna')

edited Sep 27 '19 at 07:14

answered Sep 27 '19 at 06:17

TVK

1,042
7
21

above code swap all values but I want to keep name & swap other values. – Aditya Sep 27 '19 at 06:47
Ok i edited my code to only switch names in the dicts and not the whole dicts – TVK Sep 27 '19 at 06:56
I am getting data['items'] = None when run above code. – Aditya Sep 27 '19 at 07:01
Your code working except problem is I want to keep name as on original index & want to swap other values. Your code swapping name which I do not want to do . I am trying to update your code as per my expectation. – Aditya Sep 27 '19 at 07:16

score 0 · Answer 3 · answered Sep 27 '19 at 07:07

Try this :

def switch(list, name1, name2):
    for item in list:
        if item['name'] == name1:
            item['name'] = name2
        elif item['name'] == name1:
            item['name'] = name2

    return list


data = {
   "items":[
      {
         "name":"Arvind",
         "surname":"Patel",
         "fullname":"Arvind Patel",
         "email":"abc@xyx.com"
      },
      {
         "name":"Jayesh",
         "surname":"Patel",
         "fullname":"Jayesh Patel",
         "email":"Patel@gmail.com"
      },
      {
         "name":"Krishna",
         "surname":"dave",
         "fullname":"Krishna dave",
         "email":"Krishna@xyz.com"
      },
      {
         "name":"Aditya",
         "surname":"Patel",
         "fullname":"Aditya Patel",
         "email":"Aditya@abc.com"
      }

   ]
}

data['items'] = switch(data['items'], 'Arvind', 'Jayesh')

print data

Swap values in dictionary which contain list of dictionaries?

3 Answers3

Code explenation