jsonl

About

jsonl is a Python library designed to simplify working with JSON Lines data, adhering to the JSON Lines format.

Features

• 🌎 Provides an API similar to Python's standard json module.
• 🚀 Supports custom serialization/deserialization callbacks, with the standard json module as the default.
• 🗜️ Supports compression and decompression using gzip, bzip2, and xz formats.
• 🔧 Can load files with broken lines, skipping any malformed entries.
• 📦 Includes an easy-to-use utility for incrementally writing to multiple JSON Lines files.

Installation

To install jsonl using pip, run the following command:

pip install py-jsonl

Getting Started

Dumping data to a JSON Lines File

Use jsonl.dump to write an iterable of dictionaries to a JSON Lines file:

import jsonl

data = [
    {"name": "Gilbert", "wins": [["straight", "7♣"], ["one pair", "10♥"]]},
    {"name": "May", "wins": []},
]

jsonl.dump(data, "file.jsonl")

Loading data from a JSON Lines File

Use jsonl.load to load a JSON Lines file into an iterable of objects:

import jsonl

iterable = jsonl.load("file.jsonl")
print(tuple(iterable))

Dumping data to Multiple JSON Lines Files

This example uses jsonl.dump_fork to incrementally write daily temperature data for multiple cities to separate JSON Lines files, exporting records for the first days of specified years. It efficiently manages data by creating individual files for each city, optimizing memory usage.

import datetime
import itertools
import random

import jsonl


def fetch_temperature_by_city():
    """
    Yielding filenames for each city with daily temperature data for the initial days of
    the specified years.
    """

    years = [2023, 2024]
    first_days = 10
    cities = ["New York", "Los Angeles", "Chicago"]

    for year, city in itertools.product(years, cities):
        start = datetime.datetime(year, 1, 1)
        dates = (start + datetime.timedelta(days=day) for day in range(first_days))
        daily_temperature = (
            {"date": date.isoformat(), "city": city, "temperature": round(random.uniform(-10, 35), 2)}
            for date in dates
        )
        yield (f"{city}.jsonl", daily_temperature)


# Write the generated data to files in JSON Lines format
jsonl.dump_fork(fetch_temperature_by_city())

Documentation

For more detailed information and usage examples, refer to the project documentation

Development

To contribute to the project, you can run the following commands for testing and documentation:

Running Unit Tests

Install the development dependencies and run the tests:

(env)$ pip install -r requirements-dev.txt  # Skip if already installed
(env)$ pytest tests/
(env)$ pytest --cov jsonl # Run tests with coverage

Building the Documentation

To build the documentation locally, use the following commands:

(env)$ pip install -r requirements-docs.txt   # Skip if already installed
(env)$ mkdocs serve # Start live-reloading docs server
(env)$ mkdocs build # Build the documentation site

License

This project is licensed under the MIT license.