saving a dictionary as json file

[vinay_py]

import json
with open("users.json") as datafile: 
    data = json.load(datafile)       # loaded json file data into python string
data_with_id = []                    #For addinng data with new id numbers to be used for grouping

def newdict():                       #function for adding items to new empty dictionary
    n=1000                           # variable for adding data with ID numbers in new dictionary
    for items in data:
        data_with_id.append({"idnum":n,"name":items["first_name"],"gender":items["gender"],"email":items["email"]})
        n = n+1

newdict ()
print("\nUsers with alloted ID are as below--\n")
for users in data_with_id:
   print("ID number",":" ,users["idnum"],"Name",":",users["name"],"gender",":",users["gender"],"E-Mail address",":",users["email"])
       
id_num_list = []                     #For only ID numbers added as n in newdict
for users in data_with_id:
    id_num_list.append(str(users["idnum"]))
print("\n ID numbers are : ",id_num_list)

def create_new_group(selected_ids_list):
    new_group = []
    for n in data_with_id:
        for m in selected_ids_list:
            if m in str(n["idnum"]):
                new_group.append({n["name"],n["gender"],n["email"]})
    with open("write_it.json","w") as writefile:
        writefile.write(json.dumps(new_group))
    print("\n File is saved")
    
def selection_for_grouping():    
    x = input("\nselect ID numbers by comma seperated from list to create a group : ")
    selected_ids_list = x.split(",")
    print("\nselected IDs are : ",selected_ids_list)
    for selected in selected_ids_list:
        if selected in id_num_list:
            continue
        if selected not in id_num_list:
            print("ID does not exists :",selected)
    create_new_group(selected_ids_list)

selection_for_grouping()
print("Great its done")

Error:
Traceback (most recent call last):
  File "C:\Users\Vinay.Prajapati\Desktop\Python Programs\reading json file - users - basic.py", line 51, in <module>
    selection_for_grouping()
  File "C:\Users\Vinay.Prajapati\Desktop\Python Programs\reading json file - users - basic.py", line 49, in selection_for_grouping
    create_new_group(selected_ids_list)
  File "C:\Users\Vinay.Prajapati\Desktop\Python Programs\reading json file - users - basic.py", line 36, in create_new_group
    writefile.write(json.dumps(new_group))
  File "C:\Python\Python Program\lib\json\__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "C:\Python\Python Program\lib\json\encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "C:\Python\Python Program\lib\json\encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "C:\Python\Python Program\lib\json\encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type set is not JSON serializable

The issue is with saving the new_group (selected ids by user) is not being saved in json showing error as above. the reason is its type is set instead of dictionary. so i need help what i can do here to solve this.

I also want it to save as group_name as per the name input by user string

Please note I am a bigginer, learning python and doing practice project by self.
I have recently learnt basics of python.

[buran]

what is the idea of this {n["name"],n["gender"],n["email"]}? why do you want to append a set? I guess there is some misunderstanding on your part to different container types - list, dict, set, tuple, etc.

[vinay_py]

Please note description -

1. I am reading through a .json file dictinary. takinng those users data and created a new dictionary along with allotment of a ID numbers to all of the items (userdata) of dictionary.

2. Displaying the data along with ID numbers.
3. Asking for users to select some ID numbers for grouping.

4. On the basis of selection by user I have created a new List/Dict for selected IDs user data.
Help me here i i can create a dictionary in any other ways. to quickly save it as json.

5. next i want to ask the group name from user for giving this json file name as mentioned by user.
also need help here.

---

what is the idea of this {n["name"],n["gender"],n["email"]}? why do you want to append a set? I guess there is some misunderstanding on your part to different container types - list, dict, set, tuple, etc.

Hi Buran,

Thanks for your very fast response.

please elobrate for my better understanding. I am at the bigginers level. this is my first work. I am trying all the learnt things for the first time. If you explain me i'll not make any mistake again.

[deanhystad]

A set is a container type in python, like list, tuple and dictionary. This is Python for making a set

myset={'a', 'b', 'c'}

A set is like a list, but unlike a list there can only be one of each element. This is a valid list in Python

mylist = ['a', 'b', 'c', 'a']

But if you converted the list to a set, the resulting set would only contain 'a' once.

"set" is not one of the things that json can serialize (load or dump). The code buran pointed out makes a set. If you use square brackets to make a list instead of a set, json would work. If you want to add entries to the dictionary you need to use the proper syntax for doing that (dictionary[key] = value).

[vinay_py]

A set is a container type in python, like list, tuple and dictionary. This is Python for making a set

myset={'a', 'b', 'c'}

A set is like a list, but unlike a list there can only be one of each element. This is a valid list in Python

mylist = ['a', 'b', 'c', 'a']

But if you converted the list to a set, the resulting set would only contain 'a' once.

"set" is not one of the things that json can serialize (load or dump). The code buran pointed out makes a set. If you use square brackets to make a list instead of a set, json would work. If you want to add entries to the dictionary you need to use the proper syntax for doing that (dictionary[key] = value).

Wonderfull..... Thanks a lot deanhystad. I got it now. I tried it in my code by removing {} also. I understood your point.
but now it is saving a list in new json file. and i want it the same as the file its reading from that is key:value pair way. what couuld i do next ?


agains thanks a lot for your quick replies.... :-)

[deanhystad]

The syntax for adding entries to a dictionary is dictionary[key] = value

mydict['nickname'] = 'Grumpy' would add 'nickname' to 'mydict' and assign it the value 'Grumpy'

[vinay_py]

saw some videos as per reason of error given by you both. now the code is correct and working. Thanks a lot to both of you for lightfastning replies :-).