Python | Pretty Print a dictionary with dictionary value

This article provides a quick way to pretty print a dictionary that has dictionary as values. This is required many times nowadays with the advent of NoSQL databases. Let’s code a way to perform this particular task. 

Example

Input:{'gfg': {'remark': 'good', 'rate': 5}, 'cs': {'rate': 3}}
Output: gfg: 
           remark: good
           rate: 5
        cs: 
           rate: 3

Pretty Print a Dictionary with Dictionary Value

Let us see a few ways we can pretty print a dictionary in Python whose values are also a dictionary.

• Using Nested For Loops
• Using the built-in JSON Module
• Using Recursion
• Using For Loop
• Using pprint Module

Using Nested For Loops

In this approach, we just nested for loop through each dictionary element and its corresponding values using a brute manner.

Output:

The original dictionary is : {'gfg': {'rate': 5, 'remark': 'good'}, 'cs': {'rate': 3}}
The Pretty Print dictionary is : 
gfg
rate : 5
remark : good
cs
rate : 3

Time Complexity: O(m*n) where m is the number of keys in the outer dictionary and n is the number of keys in the inner dictionary.
Auxiliary Space: O(1)

Using the built-in JSON Module

Here we will use Python’s inbuilt JSON module to print a dictionary. We will be using the json.dumps() function and pass the original dictionary as the parameter.

Output:

The original dictionary is :  {'gfg': {'rate': 5, 'remark': 'good'}, 'cs': {'rate': 3}}
The Pretty Print dictionary is : 
 {
    "gfg": {
        "rate": 5,
        "remark": "good"
    },
    "cs": {
        "rate": 3
    }
}

Time Complexity: O(n)
Auxiliary Space: O(1)

Using Recursion and String Concatenation

In this method, we will create a recursive function that will be used to print a dictionary in Python. Inside the function, a for loop iterates each element of the dictionary. Inside the loop, the function appends a string to res using the += operator. The current value is a dictionary, the function calls itself recursively with the inner dictionary and an incremented indent value. The recursive call will have to traverse through all the items in the nested dictionary. Finally, the function returns the resulting string res.

Output:

The Pretty Print dictionary is : 
gfg
    rate
        5
    remark
        good
cs
    rate
        3

Time Complexity: O(N), where N is the total number of elements in the dictionary since it iterates through each element once.

Auxiliary Space: O(N), since it stores the output string in memory, and the size of the output string is proportional to the size of the dictionary. Additionally, the recursive calls to pretty_print_dict also use stack space, which could potentially grow to O(N) in the worst-case scenario where the dictionary is deeply nested.

Using For Loop + Dictionary

For this, we will use a for loop to iterate over the keys and values of the dictionary. For each key-value pair, add the key to the string followed by a colon and a space. For each value, add it to the string followed by a newline character. Then return the pretty-printed dictionary string.

Output:

{'gfg': {'remark': 'good', 'rate': 5}, 'cs': {'rate': 3}}
gfg: 
    remark: good
    rate: 5
cs: 
    rate: 3

Time Complexity: O(n^2), where n is the number of key-value pairs in the dictionary.
Auxiliary Space: O(n), where n is the number of key-value pairs in the dictionary

Using the pprint Module

The pprint module is a built-in module in Python that provides a way to pretty-print arbitrary Python data structures in a form that can be used as input to the interpreter. It is useful for debugging and displaying complex structures.

The pretty-printed dictionary is:
{'cs': {'rate': 3}, 'gfg': {'rate': 5, 'remark': 'good'}}

The time complexity of the pprint module function pprint() depends on the size of the input dictionary.

The space complexity of the pprint module function pprint() is also dependent on the size of the input dictionary.