How to recursively iterate a nested Python dictionary?

A Dictionary in Python is a mutable, unordered collection of data in a key-value format. A dictionary can also contain another dictionary as a value and this is known as a Nested Dictionary or a dictionary within a dictionary. When working with this type of data structure, it's often important to go through each key-value pair at every level.

In this article, we will explore how to recursively iterate through a nested Python dictionary using a function-based approach.

Syntax to iterate through a Dictionary recursively

Following is a sample syntax for recursively iterating through a nested dictionary -

def recursive_iter(d):
   for key, value in d.items():
      if isinstance(value, dict):
         recursive_iter(value)
      else:print(key, ":", value)

Example to iterate through a Dictionary recursively

In this example, we define a nested dictionary with multiple dictionaries. The recursive function will print all keys and values from every level.

def recursive_iter(d):
   for key, value in d.items():
      if isinstance(value, dict):
         print(f"Entering nested dictionary at key: {key}")
         recursive_iter(value)
      else:
         print(f"{key}: {value}")

# Nested Dictionary
data = {
   'person': {
      'name': 'John',
      'age': 30,
      'address': {
         'city': 'New York',
         'zip': '10001'
      }
   },
   'job': {
      'title': 'Developer',
      'department': 'Engineering'
   }
}

# Call the function
recursive_iter(data)

Following is the output of the above program -

Entering nested dictionary at key: person
name: John
age: 30
Entering nested dictionary at key: address
city: New York
zip: 10001
Entering nested dictionary at key: job
title: Developer
department: Engineering