Skip to main content
Donate to the Python Software Foundation or Purchase a PyCharm License to Benefit the PSF! Donate Now

Reading JSON lines (jl) files, recover broken files

Project description

PyPI Version Build Status Code Coverage

This is a tiny library for reading JSON lines (.jl) files, including gzipped and broken files.

JSON lines is a text file format where each line is a single json encoded item.

Why?

Reading a well-formed JSON lines file is a one-liner in Python. But the file can be broken: cut at some point (this happens when the process writing it is killed), or concatenated from several cut pieces (this happend when the process started appending to the same file again). Handling all this cases is not easy, especially if the file is compressed.

json-lines handles all this cases for you!

Installation

pip install json-lines

If ujson is installed, it is used to speed up json decoding (which is the main performance bottleneck even for gzipped files).

Usage

In order to read a well-formed json lined file, pass an open file as the first argument to json_lines.reader. The file can be opened in text or binary mode, but if it’s opened in text mode, the encoding must be set correctly:

import json_lines

with open('file.jl', 'rb') as f:
    for item in json_lines.reader(f):
        print(item['x'])

There is also a helper function json_lines.open that recognizes “.gz” and “.gzip” extensions and opens them with gzip:

with json_lines.open('file.jl.gz') as f:
    for item in f:
        print(item['x'])

Handling broken (cut at some point) files is enabled by passing broken=True to json_lines.reader or json_lines.open. Broken lines are skipped (only logging a warning), and reading continues from the next valid position. This works both for compressed and uncompressed files:

with json_lines.open('file.jl.gz', broken=True) as f:
    for item in f:
        print(item['x'])

License

License is MIT.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
json_lines-0.5.0-py2.py3-none-any.whl (6.8 kB) Copy SHA256 hash SHA256 Wheel py2.py3
json-lines-0.5.0.tar.gz (4.3 kB) Copy SHA256 hash SHA256 Source None

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page