Formating adding nested dictionary to JSON file in specific format - json

Question

My Python script is working and appends to my JSON file; however, I have tried to add a numbered entry identification with no success. Additionally, I am trying to get a specific output each time the calculations are iterated. Looking for detailed examples and guidance.
Current Python Script
import json
# Dictionary All-Calculations
def dict_calc(num1, num2):
add = str(float(num1)+float(num2))
sub = str(float(num1)-float(num2))
mul = str(float(num1)*float(num2))
div = str(float(num1)/float(num2))
calc_d = {"Add" : add, "Subtract" : sub, "Multiply" : mul, "Divide" : div}
return calc_d
# Yes or No
def y_n(answer):
if answer[:1] == 'y':
return True
if answer[:1] == 'n':
return False
# Main Dictionary
data_table = {}
while True:
num1 = input("\n Enter first number: ")
num2 = input("\n Enter second number: ")
data_table = dict_calc(num1, num2)
with open('dict_calc.json', 'a', encoding='utf-8') as f:
json.dump(data_table, f, ensure_ascii=True, indent=4)
answer = input("\n Run Again? (Y/N) ").lower().strip()
if y_n(answer) == True:
continue
else:
print("\n Thank You and Goodbye")
break
Current Output Example
{
"Add": "579.0",
"Subtract": "-333.0",
"Multiply": "56088.0",
"Divide": "0.26973684210526316"
}{
"Add": "1245.0",
"Subtract": "-333.0",
"Multiply": "359784.0",
"Divide": "0.5779467680608364"
}{
"Add": "1396.0",
"Subtract": "554.0",
"Multiply": "410475.0",
"Divide": "2.315914489311164"
}
Desired Output Example - I am trying to add the Entry plus number, which increases after each iteration. In addition, I am also trying emulate this same output.
[
{
"Entry": "1",
"Add": "579.0",
"Subtract": "-333.0",
"Multiply": "56088.0",
"Divide": "0.26973684210526316"
},
{
"Entry": "2",
"Add": "1245.0",
"Subtract": "-333.0",
"Multiply": "359784.0",
"Divide": "0.5779467680608364"
},
{
"Entry": "3",
"Add": "1396.0",
"Subtract": "554.0",
"Multiply": "410475.0",
"Divide": "2.315914489311164"
}
]

Answer 1

JSON is a nested structure. You can't simply append more data to it. See JSON Lines format for that.
If using regular JSON format, you must read the whole JSON structure in, update it, then write it out fully again, or simply write it once the structure is complete.
Example:
import json
# Dictionary All-Calculations
def dict_calc(num1, num2, entry):
add = str(float(num1)+float(num2))
sub = str(float(num1)-float(num2))
mul = str(float(num1)*float(num2))
div = str(float(num1)/float(num2))
calc_d = {"Entry": str(entry), "Add" : add, "Subtract" : sub, "Multiply" : mul, "Divide" : div}
return calc_d
# Yes or No
def y_n(answer):
if answer[:1] == 'y':
return True
if answer[:1] == 'n':
return False
# Empty List that will hold dictionaries.
data_table = []
entry = 0 # for tracking entry numbers
while True:
num1 = input("\n Enter first number: ")
num2 = input("\n Enter second number: ")
# Count entry and add it to dictionary list.
entry += 1
data_table.append(dict_calc(num1, num2, entry))
answer = input("\n Run Again? (Y/N) ").lower().strip()
if y_n(answer) == True:
continue
else:
print("\n Thank You and Goodbye")
# Write the complete list of dictionaries in one operation.
with open('dict_calc.json', 'w', encoding='utf-8') as f:
json.dump(data_table, f, ensure_ascii=True, indent=4)
break
Output:
[
{
"Entry": "1",
"Add": "3.0",
"Subtract": "-1.0",
"Multiply": "2.0",
"Divide": "0.5"
},
{
"Entry": "2",
"Add": "8.0",
"Subtract": "-1.0",
"Multiply": "15.75",
"Divide": "0.7777777777777778"
},
{
"Entry": "3",
"Add": "13.399999999999999",
"Subtract": "-2.2",
"Multiply": "43.68",
"Divide": "0.717948717948718"
}
]

Answer 2

A few things you might need to change:
you need to change data_table type to list.
you need to append dict_calc function result to it.
Add a counter
Here is your code:
import json
# Dictionary All-Calculations
def dict_calc(counter, num1, num2):
add = str(float(num1)+float(num2))
sub = str(float(num1)-float(num2))
mul = str(float(num1)*float(num2))
div = str(float(num1)/float(num2))
calc_d = {"Entry": str(counter), "Add" : add, "Subtract" : sub, "Multiply" : mul, "Divide" : div}
return calc_d
# Yes or No
def y_n(answer):
if answer[:1] == 'y':
return True
if answer[:1] == 'n':
return False
# Main Dictionary
data_table = []
counter = 1
while True:
num1 = input("\n Enter first number: ")
num2 = input("\n Enter second number: ")
data_table.append( dict_calc(counter, num1, num2))
counter += 1
with open('dict_calc.json', 'a', encoding='utf-8') as f:
json.dump(data_table, f, ensure_ascii=True, indent=4)
answer = input("\n Run Again? (Y/N) ").lower().strip()
if y_n(answer) == True:
continue
else:
print("\n Thank You and Goodbye")
break