CODEWITHSUNDEEP
pythonjsondictionary
lord stock
lord stock

Reputation: 1201

Is there any way I can get key from values in python?(dictionary)

This question seem abit weird as I know dictionary are not intended to be used based on values rather than keys I recently came across certain problem to minimize the form fill up procedure as If certain country cities are provided then I need to autocomplete country and continent for that user. I got following Json for my reference .

[{
        "Asia": {
            "Japan": [
                "tokyo",
                "hirohima",
            ]
        }
    },
    {
        "Europe": {
            "England": [
                "Manchester",
                "London",
                "South gate",
            ]
        }
    }
]

Suppose user City is London Can I get England and Europe as Output? or Is my json formating wrong?

Upvotes: 0

Views: 133

Answers (3)

tdelaney
tdelaney

Reputation: 77347

You could create a reverse index of city to country/region tuples. Since city names are not unique, you may have the same city name in multiple countries. You could solve this by indexing to a list of country/regions. You would do this once when you get the data and then its available for quick lookup when needed.

from collections import defaultdict

data = [{
        "Asia": {
            "Japan": [
                "tokyo",
                "hirohima",
            ]
        }
    },
    {
        "Europe": {
            "England": [
                "Manchester",
                "London",
                "South gate",
            ]
        }
    }
]

reverse_index = defaultdict(list)

for region_dict in data:
    for region, country_dict in region_dict.items():
        for country, city_list in country_dict.items():
            for city in city_list:
                reverse_index[city].append((region, country))
            
for city, refs in reverse_index.items():
    print(city, refs)

Upvotes: 1

not_speshal
not_speshal

Reputation: 23146

You could loop through the data and "reverse engineer" the dictionary:

city = "London"
for d in data:
    for continent, countries in d.items():
        for country, cities in countries.items():
            if "London" in cities:
                print(country, continent)

Upvotes: 1

Mohammad Bhbouh
Mohammad Bhbouh

Reputation: 113

to get country name and continent name your json file must be in this form :

[{"ContinentName":"Asia","country":{"countryName":"Japan","cities":["tokyo","hirohima"]}},{"ContinentName":"Europe","country":{"countryName":"England","cities":["london","south gate","Manchester"]}}]

Upvotes: 1

Related Questions