To add all the values of a specific subkey for a dictionary python -

so consider dictionary.

{ "b0:47:bf:af:c1:42":  {  "no. of visits": 10, "cities":       {       "mumbai": {"count": 5,"last_visited": "5/22/2016"},       "kolkata": {"count": 2,"last_visited": "5/22/2016"},       "amritsar":{"count": 3,"last_visited": "5/22/2016"}      } }, "c0:ee:fb:71:be:0d":   {  "no. of visits": 24, "cities":       {       "mumbai": {"count": 2,"last_visited": "5/22/2016"},       "kolkata": {"count": 20,"last_visited": "5/22/2016"},       "amritsar":{"count": 2,"last_visited": "5/22/2016"}      }   }  } 

so want sum "count" "cities" output have same value "no. of visits", asking question not context. using python2.7

well iterating values when realized might need value of "no. of visits" out using it(it might not there every key).

for mac in dic_data:  cities = dic_data[mac]['cities'] most_visited = max(cities, key=lambda x: cities[x]['count']) 

so trying know how can sum of "count" of "cities" each mac.i want sum_of_count = sum(something here) gives output sum of count 10 first key , 24 second key.

you iterate through each mac address sum() counts find max(). assuming data stored in variable data, here 1 statement version:

max([sum([data[visit]["cities"][city]["count"] city in data[visit]["cities"]]) visit in data]) 

here loop version comments:

# list store total no. of visits of each mac address counts = [] mac in data:     # variable keep track of number of visits in current mac address     visits = 0     city in data[mac]["cities"]:         visits += data[mac]["cities"][city]["count"]     counts.append(visits) # highest number of visits print max(counts)