How do I add numbers from multiple for loops in python?

Question

helpp.json

{
"States":{
    "Illinois":{
        "county":[
            {
             "population":100000,
             "nameofcounty":"Dupage"   
            },
            {
                "population":200000,
                "nameofcounty":"Marion"   
               }
        ]
    },
    "Indiana":{
        "county":[
            {
             "population":100000,
             "nameofcounty":"Dupage"   
            },
            {
                "population":200000,
                "nameofcounty":"Marion"   
               }
        ]
    }
}
}

mycode

import json

with open('helpp.json') as file: 
    package_json = json.load(file)
IN = package_json['States']['Illinois']['county']
IL = package_json['States']['Indiana']['county']

for i in IN:
    county = i['nameofcounty']
    population = i['population']
for j in IL:
    population = j['population']
    county = j['nameofcounty']

    total_population = i['population']+j['population']
    print(county,total_population)

I cant figure out how to add numbers from multiple for loops correctly. my current output is Dupage 300000 Marion 400000 but its suppose to be Dupage 200000 Marion 400000.

Answer 1

The simple error which you are doing in your code is the second last line wherein you are adding i['population'] with j['population'. Herein, the first for loop has been exited so the code takes the last value of i to be 200000 (population of Marion). Thus, to prevent this error you can firstly have different names because I don't really know why would you define population 2 different times for 2 different datasets with the same variable. Here are some of the ways you can go through it:

import json
with open('test.json') as file: 
    package_json = json.load(file)
IN = package_json['States']['Illinois']['county']
IL = package_json['States']['Indiana']['county']

for i in IN:
    county = i['nameofcounty']
    population = i['population']
    for j in IL:
        population_1 = j['population']
        county_1 = j['nameofcounty']
        if county_1 == county: #To check if they are the same thing
            total_population = population_1+population #adds them
            print(county, total_population) #Print

This method above is however not so efficient. I personally suggest trying:

import json    
with open('test.json') as file: 
    package_json = json.load(file)
IN = package_json['States']['Illinois']['county']
IL = package_json['States']['Indiana']['county']

for i,j in zip(IN,IL): #zip() basically makes it combined
    print(i['nameofcounty'],i['population']+j['population'])

Both have the same output, but the second one is more efficient in your case. For more info about zip() you can check the docs