You can find a dict index by counting into the dict. keys() with a loop. If you use the enumerate() function, it will generate the index values automatically.
Accessing Elements from DictionaryKeys can be used either inside square brackets [] or with the get() method. If we use the square brackets [] , KeyError is raised in case a key is not found in the dictionary. On the other hand, the get() method returns None if the key is not found.
3. Access values in a dictionary. To access dictionary values, we cannot use a numeric index (as we do with lists or tuples), since the dictionaries are unordered containers.
Given that it is a dictionary you access it by using the keys. Getting the dictionary stored under "Apple", do the following:
>>> mydict["Apple"]
{'American': '16', 'Mexican': 10, 'Chinese': 5}
And getting how many of them are American (16), do like this:
>>> mydict["Apple"]["American"]
'16'
If the questions is, if I know that I have a dict of dicts that contains 'Apple' as a fruit and 'American' as a type of apple, I would use:
myDict = {'Apple': {'American':'16', 'Mexican':10, 'Chinese':5},
'Grapes':{'Arabian':'25','Indian':'20'} }
print myDict['Apple']['American']
as others suggested. If instead the questions is, you don't know whether 'Apple' as a fruit and 'American' as a type of 'Apple' exist when you read an arbitrary file into your dict of dict data structure, you could do something like:
print [ftype['American'] for f,ftype in myDict.iteritems() if f == 'Apple' and 'American' in ftype]
or better yet so you don't unnecessarily iterate over the entire dict of dicts if you know that only Apple has the type American:
if 'Apple' in myDict:
if 'American' in myDict['Apple']:
print myDict['Apple']['American']
In all of these cases it doesn't matter what order the dictionaries actually store the entries. If you are really concerned about the order, then you might consider using an OrderedDict
:
http://docs.python.org/dev/library/collections.html#collections.OrderedDict
As I noticed your description, you just know that your parser will give you a dictionary that its values are dictionary too like this:
sampleDict = {
"key1": {"key10": "value10", "key11": "value11"},
"key2": {"key20": "value20", "key21": "value21"}
}
So you have to iterate over your parent dictionary. If you want to print out or access all first dictionary keys in sampleDict.values()
list, you may use something like this:
for key, value in sampleDict.items():
print value.keys()[0]
If you want to just access first key of the first item in sampleDict.values()
, this may be useful:
print sampleDict.values()[0].keys()[0]
If you use the example you gave in the question, I mean:
sampleDict = {
'Apple': {'American':'16', 'Mexican':10, 'Chinese':5},
'Grapes':{'Arabian':'25','Indian':'20'}
}
The output for the first code is:
American
Indian
And the output for the second code is:
American
EDIT 1:
Above code examples does not work for version 3 and above of python; since from version 3, python changed the type of output of methods keys
and values
from list
to dict_values
. Type dict_values
is not accepting indexing, but it is iterable. So you need to change above codes as below:
First One:
for key, value in sampleDict.items():
print(list(value.keys())[0])
Second One:
print(list(list(sampleDict.values())[0].keys())[0])
I know this is 8 years old, but no one seems to have actually read and answered the question.
You can call .values() on a dict to get a list of the inner dicts and thus access them by index.
>>> mydict = {
... 'Apple': {'American':'16', 'Mexican':10, 'Chinese':5},
... 'Grapes':{'Arabian':'25','Indian':'20'} }
>>>mylist = list(mydict.values())
>>>mylist[0]
{'American':'16', 'Mexican':10, 'Chinese':5},
>>>mylist[1]
{'Arabian':'25','Indian':'20'}
>>>myInnerList1 = list(mylist[0].values())
>>>myInnerList1
['16', 10, 5]
>>>myInnerList2 = list(mylist[1].values())
>>>myInnerList2
['25', '20']
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With