I have 3 different dictionaries in python like these
d1 = {'simple_key':'hello'}
d2 = {'k1':{'k2':'hello'}}
d3 = {'k1':[{'nest_key':['this is deep',['hello']]}]}
and I want to grab the word 'hello' from these dictionaries. But the problem I am facing is that I want to find a generic way to extract it. How can I do it?
To get the key path in the dict using value, you could flatten it as json.
>>> from json_flatten import flatten
>>> d1 = {'simple_key':'hello'}
>>> d2 = {'k1':{'k2':'hello'}}
>>> d3 = {'k1':[{'nest_key':['this is deep',['hello']]}]}
>>> flatten(d2)
{'k1.k2': 'hello'}
>>> flat = flatten(d3)
{'k1.0.nest_key.0': 'this is deep', 'k1.0.nest_key.1.0': 'hello'}
To find the matching keys, use,
>>> [k for k, v in flat.items() if v == 'hello']
['k1.0.nest_key.1.0']
You can keep going inside the dictionary until you are at a value, not a dictionary. Recursion would be helpful here:
def get_value(dict):
dict_value = list(dict.values())[0]
if type(dict_value) is dict:
get_value(dict_value)
else:
return dict_value
there is probably a nicer way to do dict_value = list(dict.values())[0] but not coming to mind right now
You could make your own flattener function which yields the values in a dict and members of a list:
def is_nonstring_iterable(x):
return ((hasattr(x, "__iter__") or hasattr(x, "__getitem__"))
and not isinstance(x, str))
def flatten(thing):
""" Recursively iterate through values in dictionary-like object or members
in lists, tuples or other non-string iterables """
if hasattr(thing, "values"):
thing = thing.values()
if is_nonstring_iterable(thing):
for element in thing:
yield from flatten(element)
else:
yield thing
for d in [d1, d2, d3]:
print(list(flatten(d)))
print(any(item == "hello" for item in flatten(d))) # returns whether hello is found
dictionary[key1][key2]...[keyN]is a generic way to get to any element. Or do you simply want to check that there is "hello" somewhere as a value?if "hello" in json.dumps(d1)?