Python: Convert a list into a nested dictionary of keys

Last update on June 28 2025 12:40:19 (UTC/GMT +8 hours)

27. Convert List into Nested Dictionary of Keys

Write a Python program to convert a list into a nested dictionary of keys.

Sample Solution:

Python Code:

# Create a list 'num_list' containing numbers.
num_list = [1, 2, 3, 4]

# Create an empty dictionary 'new_dict' and initialize 'current' to reference the same dictionary.
new_dict = current = {}

# Iterate through the numbers in 'num_list' using a for loop.
for name in num_list:
    # Create a nested empty dictionary under the 'current' dictionary with the current 'name' as the key.
    current[name] = {}
    
    # Update the 'current' reference to point to the newly created nested dictionary.
    current = current[name]

# Print the 'new_dict' dictionary, which is a nested structure with empty dictionaries.
print(new_dict)

Sample Output:

{1: {2: {3: {4: {}}}}}

For more Practice: Solve these Related Problems:

Write a Python program to recursively convert a list of elements into a nested dictionary, where each element is a key.
Write a Python program to create a nested dictionary from a list using a for-loop and dictionary assignment.
Write a Python program to use recursion to transform a list into a nested dictionary structure with each element as a key.
Write a Python program to implement a function that returns a nested dictionary representation of a list of items.

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