Python Search for a specific value in a nested dictionary and get one dictionary including the value-CodePudding

I am trying to get a dictionary that includes a specific value from nested dictionaries.

My multiple dictionaries look like this:

MyDto = [{'app' : 'chrome',
'id': 'adetwt',
'name': 'John',
'selection': {'food':1324, 'var1': 2039, 'var2': 2126, 'var3': 0}},
{'app' : 'chrome',
'id': 'asdfb',
'name': 'Sam',
'selection': {'food':1324, 'var1': 2011, 'var2': 2123, 'var3': 0}},
{'app' : 'chrome',
'id': 'sfsf',
'name': 'Mary',
'selection': {'food':1324, 'var1': 2013, 'var2': 2111, 'var3': 0}}]

I want to only get a dictionary with a specific value. For example, in this example,

if MyDto['id'] = 'sfsf'

The result I want to get is

extracted_dict = {'app' : 'chrome',
'id': 'sfsf',
'name': 'Mary',
'selection': {'food':1324, 'var1': 2013, 'var2': 2111, 'var3': 0}

Is there a way to get a dictionary based on a specific value it includes? Sorry if this is too basic question :( Thanks a lot!

CodePudding user response：

I would go with something like:

key,value = 'id','sfsf'
dictList = [ myDict for myDict in MyDto if myDict.get(key) == value ]
print(dictList)

output

[{'app': 'chrome', 'id': 'sfsf', 'name': 'Mary', 'selection': {'food': 1324, 'var1': 2013, 'var2': 2111, 'var3': 0}}]

The list comprehension obviously produces a list of dicts and not a single dict. With this list comprehension you scan all the dicts in your MyDto, and select only the ones which contain the pair key/value you chose. It also works if the key is not present in any dictionary in MyDto, that is it avoids a KeyError exception and produces and empty list.

If you are sure that at most only one dict with key/value is contained in the list:

def getByKeyAndValue(dictList, key, value):
        for myDict in dictList:
            if myDict.get(key) == value:
                return myDict
        return {}

extracted_dict = getByKeyAndValue(MyDto, 'id', 'sfsf')

This function scans your MyDto only until it finds the dict you want to extract. If it does not find the dict, it returns an empty dict.

CodePudding user response：

Just iterate over items and get the right dict as below:

MyDto = [
    {'app': 'chrome',
     'id': 'adetwt',
     'name': 'John',
     'selection': {'food': 1324, 'var1': 2039, 'var2': 2126, 'var3': 0}},
    {'app': 'chrome',
     'id': 'asdfb',
     'name': 'Sam',
     'selection': {'food': 1324, 'var1': 2011, 'var2': 2123, 'var3': 0}},
    {'app': 'chrome',
     'id': 'sfsf',
     'name': 'Mary',
     'selection': {'food': 1324, 'var1': 2013, 'var2': 2111, 'var3': 0}}
]


def get_by_id(id: str):
    for dict_ in MyDto:
        if dict_['id'] == id:
            return dict_['selection']


print(get_by_id('sfsf'))

CodePudding user response：

gotta love list comprehension:

[d for d in MyDto if d['id'] == 'sfsf']