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

Quote: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.

Quote: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.

(Jun-06-2020, 04:12 PM)buran Wrote: 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.

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

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

(Jun-06-2020, 04:42 PM)deanhystad Wrote: 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).