Python – Convert Dictionaries List to Order Key Nested dictionaries

Given list of dictionaries, convert to ordered key dictionary with each key contained dictionary as its nested value.

Input : test_list = [{“Gfg” : 3, 4 : 9}, {“is”: 8, “Good” : 2}]
Output : {0: {‘Gfg’: 3, 4: 9}, 1: {‘is’: 8, ‘Good’: 2}}
Explanation : List converted to dictionary with index keys.

Input : test_list = [{“is”: 8, “Good” : 2}]
Output : {1: {‘is’: 8, ‘Good’: 2}}
Explanation : List converted to dictionary with index keys, just one row.

Method #1 : Using loop + enumerate()

This is brute way in which this task can be performed. In this, we iterate through the index and value together using enumerate and create custom required dictionary.

Python3

# Python3 code to demonstrate working of
# Convert Dictionaries List to Order Key Nested dictionaries
# Using loop + enumerate()

# initializing lists
test_list = [{"Gfg" : 3, 4 : 9}, {"is": 8, "Good" : 2}, {"Best": 10, "CS" : 1}]

# printing original list
print("The original list : " + str(test_list))

# using enumerate() to extract key to map with dict values
res = dict()
for idx, val in enumerate(test_list):
    res[idx] = val

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

Output

The original list : [{'Gfg': 3, 4: 9}, {'is': 8, 'Good': 2}, {'Best': 10, 'CS': 1}]
The constructed dictionary : {0: {'Gfg': 3, 4: 9}, 1: {'is': 8, 'Good': 2}, 2: {'Best': 10, 'CS': 1}}

Method #2 : Using dictionary comprehension + enumerate() 

This is similar to above method, the only difference is that dictionary comprehension is used instead of loop to perform task of encapsulation.

Python3

# Python3 code to demonstrate working of
# Convert Dictionaries List to Order Key Nested dictionaries
# Using dictionary comprehension + enumerate()

# initializing lists
test_list = [{"Gfg" : 3, 4 : 9}, {"is": 8, "Good" : 2}, {"Best": 10, "CS" : 1}]

# printing original list
print("The original list : " + str(test_list))

# dictionary comprehension encapsulating result as one liner
res = {idx : val for idx, val in enumerate(test_list)}

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

Output

The original list : [{'Gfg': 3, 4: 9}, {'is': 8, 'Good': 2}, {'Best': 10, 'CS': 1}]
The constructed dictionary : {0: {'Gfg': 3, 4: 9}, 1: {'is': 8, 'Good': 2}, 2: {'Best': 10, 'CS': 1}}