Write JSON data to a file in Python

This post will discuss how to read and write JSON data from a file in Python.

The standard way to read and write JSON data from a file is using the json module.

To read a JSON file, you can simply call the json.loads() function.

import json

import pprint

with open('data.json', 'r') as f:

data = f.read()

json_data = json.loads(data)

print(json_data)

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To write JSON to a file, call the json.dumps() function.

import json

json_obj = json.loads('{"one": 1, "two": 2, "three": 3}')

with open('data.json', 'w') as f:

json.dump(json_obj, f)

'''

data.json:

{"one": 1, "two": 2, "three": 3}

'''

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The json.dumps() function selects the most compact representation of json by default. For pretty-printing the json, you can specify the indent argument.

1. A positive indent level indents that many spaces per level, i.e., JSON will be pretty-printed with that indent level.

import json

json_str = '{"one": 1, "two": 2, "three": 3}'

json_obj = json.loads(json_str)

with open('data.json', 'w') as f:

json.dump(json_obj, f, indent=2)

'''

data.json:

{

"one": 1,

"two": 2,

"three": 3

}

'''

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2. If the indent is a string (such as '\t'), that string will indent each level.

import json

json_str = '{"one": 1, "two": 2, "three": 3}'

json_obj = json.loads(json_str)

with open('data.json', 'w') as f:

json.dump(json_obj, f, indent='\t')

'''

data.json:

{

"one": 1,

"two": 2,

"three": 3

}

'''

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3. A zero or negative indent level or an empty string will only insert newlines.

import json

json_str = '{"one": 1, "two": 2, "three": 3}'

json_obj = json.loads(json_str)

with open('data.json', 'w') as f:

json.dump(json_obj, f, indent=0)

'''

data.json:

{

"one": 1,

"two": 2,

"three": 3

}

'''

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That’s all about writing JSON data to a file in Python.

Write JSON data to a file in Python

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