Flattening JSON objects in Python

{'user': {'Rachel': {'UserID': 1717171717, 'Email': 'rachel1999@gmail.com', 'friends': ['John', 'Jeremy', 'Emily']}}}

{'user_Rachel_UserID': 1717171717, 'user_Rachel_Email': 'rachel1999@gmail.com', 'user_Rachel_friends_0': 'John', 'user_Rachel_friends_1': 'Jeremy', 'user_Rachel_friends_2': 'Emily'}

Need of flattening JSON

There are many reasons for the need of flattening JSON, such as for a better and understandable view that is there are only key-value pairs are present without any nesting. It also allows for context-specific security and constraints to be implemented in a readable, but in more verbose way.

Approach to flatten JSON

There are many ways to flatten JSON. There is one recursive way and another by using the json-flatten library.

• Recursive Approach: Now we can flatten the dictionary array by a recursive approach which is quite easy to understand. The recursive approach is a bit slower than using json-flatten library

# for a array value of a key 
unflat_json = {'user' : 
			{'Rachel': 
				{'UserID':1717171717, 
				'Email': 'rachel1999@gmail.com', 
				'friends': ['John', 'Jeremy', 'Emily'] 
				} 
			} 
			} 

# Function for flattening 
# json 
def flatten_json(y): 
	out = {} 

	def flatten(x, name =''): 
		
		# If the Nested key-value 
		# pair is of dict type 
		if type(x) is dict: 
			
			for a in x: 
				flatten(x[a], name + a + '_') 
				
		# If the Nested key-value 
		# pair is of list type 
		elif type(x) is list: 
			
			i = 0
			
			for a in x:				 
				flatten(a, name + str(i) + '_') 
				i += 1
		else: 
			out[name[:-1]] = x 

	flatten(y) 
	return out 

# Driver code 
print(flatten_json(unflat_json)) 

{'user_Rachel_UserID': 1717171717, 'user_Rachel_Email': 'rachel1999@gmail.com', 'user_Rachel_friends_0': 'John', 'user_Rachel_friends_1': 'Jeremy', 'user_Rachel_friends_2': 'Emily'}

Installing library

In order to use the flatten_json library, we need to install this library. flatten_json can be installed by running the following command in the terminal.

pip install json-flatten

from flatten_json import flatten 

unflat_json = {'user' : 
			{'Rachel': 
				{'UserID':1717171717, 
				'Email': 'rachel1999@gmail.com', 
				'friends': ['John', 'Jeremy', 'Emily'] 
				} 
			} 
			} 

flat_json = flatten(unflat_json) 

print(flat_json) 

{'user_Rachel_UserID': 1717171717, 'user_Rachel_Email': 'rachel1999@gmail.com', 'user_Rachel_friends_0': 'John', 'user_Rachel_friends_1': 'Jeremy', 'user_Rachel_friends_2': 'Emily'}