data is a Python dictionary. It needs to be encoded as JSON before writing.
Use this for maximum compatibility (Python 2 and 3):
import json
with open('data.json', 'w') as f:
json.dump(data, f)
On a modern system (i.e. Python 3 and UTF-8 support), you can write a nicer file using:
import json
with open('data.json', 'w', encoding='utf-8') as f:
json.dump(data, f, ensure_ascii=False, indent=4)
See json documentation.
Top answer 1 of 16
3357
data is a Python dictionary. It needs to be encoded as JSON before writing.
Use this for maximum compatibility (Python 2 and 3):
import json
with open('data.json', 'w') as f:
json.dump(data, f)
On a modern system (i.e. Python 3 and UTF-8 support), you can write a nicer file using:
import json
with open('data.json', 'w', encoding='utf-8') as f:
json.dump(data, f, ensure_ascii=False, indent=4)
See json documentation.
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347
To get utf8-encoded file as opposed to ascii-encoded in the accepted answer for Python 2 use:
import io, json
with io.open('data.txt', 'w', encoding='utf-8') as f:
f.write(json.dumps(data, ensure_ascii=False))
The code is simpler in Python 3:
import json
with open('data.txt', 'w') as f:
json.dump(data, f, ensure_ascii=False)
On Windows, the encoding='utf-8' argument to open is still necessary.
To avoid storing an encoded copy of the data in memory (result of dumps) and to output utf8-encoded bytestrings in both Python 2 and 3, use:
import json, codecs
with open('data.txt', 'wb') as f:
json.dump(data, codecs.getwriter('utf-8')(f), ensure_ascii=False)
The codecs.getwriter call is redundant in Python 3 but required for Python 2
Readability and size:
The use of ensure_ascii=False gives better readability and smaller size:
>>> json.dumps({'price': '€10'})
'{"price": "\\u20ac10"}'
>>> json.dumps({'price': '€10'}, ensure_ascii=False)
'{"price": "€10"}'
>>> len(json.dumps({'абвгд': 1}))
37
>>> len(json.dumps({'абвгд': 1}, ensure_ascii=False).encode('utf8'))
17
Further improve readability by adding flags indent=4, sort_keys=True (as suggested by dinos66) to arguments of dump or dumps. This way you'll get a nicely indented sorted structure in the json file at the cost of a slightly larger file size.
GeeksforGeeks
geeksforgeeks.org › python › reading-and-writing-json-to-a-file-in-python
Reading and Writing JSON to a File in Python - GeeksforGeeks
It takes two parameters: dictionary: ... indentation · After converting the dictionary to a JSON object, simply write it to a file using the "write" function....
Published: August 5, 2025
How would you use python to create JSON files?
From StackOverflow JSON is basically a way of communicating data to someone, with very specific rules. Using Key Value Pairs and Arrays. JSON is very lightweight and is a nice way to store information. If you request a web-server, most responses will be in JSON format. Example of JSON data (also from StackOverflow): { "first_name": "John", "last_name": "Smith", "address": { "street_address": "21 2nd Street", "city": "New York", "state": "NY", "postal_code": 10021 }, "phone_numbers": [ "212 555-1234", "646 555-4567" ] } Now, to answer your question. How to create JSON files using Python? First, you need valid JSON in your Python code. images = [ { "name": "awesome_image.png", "file_size": 1240000, "file_type": "image/png", }, { "name": "good_image.jpg", "file_size": 742600, "file_type": "image/jpeg" } ] Now, using the json library # Load data. This will transform the data into an indented string. json_data = json.dumps(images, indent=2) # Create and write to file. with open("/home/user/Documents/images.json", "w") as json_file: json_file.write(json_data) How to load JSON files in Python? # Open file in read mode. with open("/home/user/Documents/images.json", "r") as f: # We can do this in two ways. # 1. Load file directly. data = json.load(f) # 2. Load from the file's contents. data = json.loads(f.read()) Now all the file content is stored in the data variable. If you are dealing with files, it's better to load and work with them in Python. It'll be faster than to keep opening and closing files all the time. Create functions to write/load files and use them when you need to. More on reddit.com
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5
March 7, 2020How do i save what i write in here to a json file?
How do i save what i write in here to a json file · If you want all of the text, give the start index as '1.0' (line 1, column 0) and the end index as 'end' · Note that after root.mainloop() returns, the widget won’t exist any longer, so here I’m getting it when the window closes: More on discuss.python.org
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February 6, 2025Proper way to open and write json files?
You should try to minimize file opening/closing operations. In general, the syntax to follow is: with open(FILENAME, MODE) as FILE_DESCRIPTOR_ALIAS: # DO OPERATIONS HERE MODE will determine the kinds of and behavior of input-output actions you can perform with the file. See this fantastic thread on the matter . So the typical workflow is: open a file, read in its contents, modify said contents, save the modified contents back to the file. The typical mode used for this kind of workflow is r+ More on reddit.com
4
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December 22, 2021write json file to variable in python
JSON_DUMP = print(READFILE.read()) print() doesn't return anything, so by wrapping READFILE.read() here you're throwing away the file and returning None. Even if you had successfully saved the data, the json parameter of requests.post() expects a python object, not a string, so you'd probably want to have converted the file from a json string to a python object. You can do this like with open('state_info.txt') as f: data = json.load(f) r = requests.post(url=WEBHOOK, json=data) print(r.content) More on reddit.com
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August 24, 202307:42
Working with Files in Python #8 - Working with JSON Files - YouTube
08:06
Python! Reading and Writing JSON Files - YouTube
03:30
How to Work with JSON Data in Python | Parse, Read & Write JSON ...
09:25
How to Read and Write JSON File in Python #json #python - YouTube
OneUptime
oneuptime.com › home › blog › how to read and write json files in python
How to Read and Write JSON Files in Python
January 25, 2026 - To write Python data to a JSON file, use json.dump():
Sentry
sentry.io › sentry answers › python › write json data to a file in python
Write to JSON File in Python Using json.dump() | Sentry
Use Python's built-in json.dump() to serialize dictionaries to JSON files with formatting options like indent and sort_keys, plus json.load() to read them back
Reddit
reddit.com › r/learnpython › how would you use python to create json files?
r/learnpython on Reddit: How would you use python to create JSON files?
March 7, 2020 -
Howdy!
I recently took a coding test for an internship program, I was quickly put in check by the coding test. I am only about 50 hours into coding, but I had higher hopes for myself then how I performed.
The questions that tripped me up were how to take input in the form of a Dict [] and create a JSON object out of it. I was allowed to read documentation during the test and found the JSON library with json.dumps, but couldn't figure out how to use it in the allotted time. =^(
In the spirit of improvement would you fine folks of r/learnpython be willing to show how you would create a JSON object with python, and outline some reasons as to why you would want to create a JSON object in the first place? I'm hoping to learn something new, but I also hope that there are a few on this sub who can come across the post and learn something new too.
On the bright side, I solved FizzBuzz no problem. That problem gave me anxiety when I first started coding, and now I can solve it expertly. Little wins!
Thank you! =^)
Top answer 1 of 4
5
I read two concrete questions from your post: why you would want to create a JSON object Imagine you want multiple software systems to communicate. Let's say we have three systems, one written in Python, one client written in JavaScript and one more backend system in Java. You can't just send Python objects over a network and expect the systems written in JS or Java to understand them. Same thing the other way around. In the end it's just electrical signals and both the sender and receiver need a common understanding of how to interpret those signals, otherwise they will just be gibberish. That's where data formats like JSON come into play: It's a simple and standardized data format that can be handled in any modern programming language. Now your Python code can serialize its internal representation of a piece of data into this format and send it over a network or store it on some disk, where some other system will eventually pick it up, deserialize it into its own internal representation and process it. show how you would create a JSON object with python import json data = {"year": 2020, "sales": 12345678, "currency": "€"} # creating a JSON string json_string = json.dumps(data) # storing it in a file with open("data.json", "w") as json_file: json.dump(data, json_file)
2 of 4
3
If you know about the JSON library, there's not much more to tell. RealPython have excellent tutorials and information. https://realpython.com/python-json/ You can find a lot more by searching "python json tutorial".
Imperial College London
python.pages.doc.ic.ac.uk › java › lessons › java › 10-files › 04-dump.html
Python for Java Programmers > Writing to JSON files | Department of Computing | Imperial College London
The following code serialises data ... as jsonfile: json.dump(data, jsonfile) To write your data to a string (and do something else with it later), use json.dumps()....
CodeSignal
codesignal.com › learn › courses › hierarchical-and-structured-data-formats › lessons › constructing-objects-and-writing-to-json-files
Constructing Objects and Writing to JSON Files
It offers simple functions to convert between Python objects and JSON. To write our data to a JSON file, we'll use the json.dump() function, which serializes Python objects into JSON format and writes it to a file.
CCMC
ccmc.gsfc.nasa.gov › scoreboards › sep › writing-sepsb-json-guide
How to write your data to a JSON file | NASA CCMC
The best way to write your data to a JSON file is to load the JSON library for your language and use it to write out a JSON file. This is the best method to ensure that the JSON is properly formatted.
Python
docs.python.org › 3 › library › json.html
json — JSON encoder and decoder
Serialize obj as a JSON formatted stream to fp (a .write()-supporting file-like object) using this Python-to-JSON conversion table.
Code Institute
codeinstitute.net › blog › python › working with json in python: a beginner’s guide
Working with JSON in Python: A Beginner's Guide - Code Institute Global
February 6, 2024 - To store JSON data in a file, you can use the `json` module, which is part of the Python standard library.
Python.org
discuss.python.org › python help
How do i save what i write in here to a json file? - Python Help - Discussions on Python.org
February 6, 2025 - How do i save what i write in here to a json file · If you want all of the text, give the start index as '1.0' (line 1, column 0) and the end index as 'end' · Note that after root.mainloop() returns, the widget won’t exist any longer, so here I’m getting it when the window closes:
Medium
medium.com › @ryan_forrester_ › writing-json-to-a-file-in-python-a-step-by-step-guide-630584957d07
Writing JSON to a File in Python: A Step-by-Step Guide | by ryan | Medium
November 6, 2024 - The first step in writing JSON data to a file is to import the `json` module. This module contains methods for parsing and writing JSON data. ... - The `import` statement brings in the `json` module, which allows us to use its functions without ...
Real Python
realpython.com › python-json
Working With JSON Data in Python – Real Python
August 20, 2025 - JSON is a good data format to use with Python as it’s human-readable and straightforward to serialize and deserialize, which makes it ideal for use in APIs and data storage. You write JSON with Python using json.dump() to serialize data to a file.
Leapcell
leapcell.io › blog › how-to-write-json-to-a-file-in-python
How to Write JSON to a File in Python | Leapcell
July 25, 2025 - Use Python's built-in json module for JSON file operations. json.dump() writes Python dictionaries to a file as JSON.
Better Stack
betterstack.com › community › questions › how-to-write-json-data-to-file-in-python
How do I write JSON data to a file in Python? | Better Stack Community
You can use the json module in Python to write JSON data to a file. The module has a dump() function that can be used to write JSON data to a file-like object.
Scaler
scaler.com › home › topics › read, write, parse json file using python
Read, Write, Parse JSON File Using Python - Scaler Topics
April 17, 2024 - Writing JSON data to a file is a common task in Python, especially when dealing with data persistence or data exchange between different systems. The json module in Python allows you to convert data structures to JSON strings using json.dumps() and provides a convenient way to write JSON data ...
W3Schools
w3schools.com › PYTHON › python_json.asp
Python JSON
JSON is text, written with JavaScript object notation. Python has a built-in package called json, which can be used to work with JSON data.
DataCamp
datacamp.com › tutorial › json-data-python
Python JSON Data: A Guide With Examples | DataCamp
December 3, 2024 - Configuration Files. JSON provides a simple and easy-to-read format for storing and retrieving configuration data. This can include settings for the application, such as the layout of a user interface or user preferences. IoT (Internet of Things). IoT devices often generate large amounts of data, which can be stored and transmitted between sensors and other devices more efficiently using JSON. python_obj = { "name": "John Doe", "age": 30, "email": "john.doe@example.com", "is_employee": True, "hobbies": [ "reading", "playing soccer", "traveling" ], "address": { "street": "123 Main Street", "city": "New York", "state": "NY", "zip": "10001" } } print(python_obj)
YouTube
youtube.com › watch
JSON in Python - Writing to Files - YouTube
Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.
Published: April 15, 2025
How Tos JSON
campbell-muscle-lab.github.io › howtos_json › pages › in_code › python › writing › writing.html
Writing JSON Files - How Tos JSON
# Import the json module for reading/writing JSONs. import json # Describe the file path where you would like to save the JSON file. JSON_FILE_PATH = "python_writing_demo.json" # Form the dictionary that we would like to write. Notice how close this syntax # is to the JSON structure!