Python – Distinct Flatten dictionaries

Sometimes, while working with dictionaries, we can have keys which in itself is a part of very complex nestings and we wish to extract all the keys and values of particular key nesting into a separate list. This kind of problem can have applications in many domains such as web development. Lets discuss certain ways in which this task can be performed.
Method #1 : Using loop + isinstance() + list comprehension
The combination of above functions can be used to solve this problem. In this, we perform the task of flattening dictionary using checks with isinstance() and loop. At last list comprehension is used to compile the result in the form of dictionary list.

Python3

# Python3 code to demonstrate working of
# Distinct Flatten dictionaries
# Using loop + isinstance() + list comprehension

def flatten(temp_dict, temp_list):
    for key, val in temp_dict.items():
        if isinstance(val, dict):
            temp_list.append(key)
            flatten(val, temp_list)
        else:
            temp_list.extend([key, val])
    return temp_list

# initializing dictionary
test_dict = {'gfg' : {'is' : 4, "best" : 10}, 'is' : {'for' : { 'geeks' : 8 }}}

# printing original dictionary
print("The original dictionary is : " + str(test_dict))

# Distinct Flatten dictionaries
# Using loop + isinstance() + list comprehension
res = [flatten(val, [key]) for key, val in test_dict.items()]

# printing result
print("The flattened dictionary elements : " + str(res))

Output : 

The original dictionary is : {'is': {'for': {'geeks': 8}}, 'gfg': {'is': 4, 'best': 10}} 
The flattened dictionary elements : [['is', 'for', 'geeks', 8], ['gfg', 'is', 4, 'best', 10]]  

Method #2 : Using yield + isinstance()
This task can also be performed using combination of above functions. In this, we use dynamic data rendering using yield to make process compact and readable.

Python3

# Python3 code to demonstrate working of
# Distinct Flatten dictionaries
# Using yield + isinstance()

def flatten(temp_dict):
    if isinstance(temp_dict, dict):
        for key, val in temp_dict.items():
            yield key
            yield from flatten(val)
    else:
        yield temp_dict

# initializing dictionary
test_dict = {'gfg' : {'is' : 4, "best" : 10}, 'is' : {'for' : { 'geeks' : 8 }}}

# printing original dictionary
print("The original dictionary is : " + str(test_dict))

# Distinct Flatten dictionaries
# Using yield + isinstance()
res = [[key, *flatten(val)] for key, val in test_dict.items()]

# printing result
print("The flattened dictionary elements : " + str(res))

Output : 

The original dictionary is : {'is': {'for': {'geeks': 8}}, 'gfg': {'is': 4, 'best': 10}} 
The flattened dictionary elements : [['is', 'for', 'geeks', 8], ['gfg', 'is', 4, 'best', 10]]