JSON to CSV Converter · Snippets Library

Sometimes you need to convert an API response or dataset from JSON into a spreadsheet‑friendly format. This Python script reads a JSON file containing an array of objects, determines the field names, and writes them to a CSV file. It uses the built‑in json and csv modules—no external dependencies required.

import json
import csv
from pathlib import Path
 
def json_to_csv(json_path: str, csv_path: str) -> None:
    with open(json_path, 'r', encoding='utf-8') as f:
        data = json.load(f)
    if not data:
        return
    keys = sorted({k for item in data for k in item.keys()})
    with open(csv_path, 'w', encoding='utf-8', newline='') as f:
        writer = csv.DictWriter(f, fieldnames=keys)
        writer.writeheader()
        writer.writerows(data)
 
if __name__ == '__main__':
    import sys
    if len(sys.argv) != 3:
        print("Usage: python json_to_csv.py input.json output.csv")
        sys.exit(1)
    json_to_csv(sys.argv[1], sys.argv[2])

Run this script from the command line: python json_to_csv.py data.json data.csv. It produces a CSV file with all object keys as columns. Modify it to suit nested structures or specific field ordering.