jsonslicer

library0.1.8pypypiunverified

JsonSlicer is a Python library (version 0.1.8) designed for efficient stream or iterative JSON parsing. It processes JSON documents without loading the entire structure into memory, making it suitable for very large files or streams. Written in C and leveraging the YAJL JSON parsing library, it offers high performance. JsonSlicer provides an iterator interface to extract specific data by defining paths using map keys and array indices, yielding matching JSON data as complete Python objects. Its release cadence is irregular, with minor updates addressing compatibility and performance.

serialization data

pip install jsonslicer

github ↗package ↗

INSTALL

IMPORT

SIG · JSONSLICER

jsonslicer

serializationpythonv0.1.8

Install

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Import

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Disk

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Pass rate

0/ 10

Env Coverage0 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v? · pip install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.920 runs

build_error

glibc

py 3.10–3.920 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

JsonSlicer

✓ from jsonslicer import JsonSlicer

This quickstart demonstrates how to extract specific values and iterate over collections within a JSON file using `JsonSlicer`. It shows direct path extraction and the use of `None` as a wildcard for iterating through arrays or dictionary values.

import os import json from jsonslicer import JsonSlicer # Create a dummy JSON file for demonstration data = { "friends": [ {"name": "John", "age": 31}, {"name": "Ivan", "age": 26} ], "colleagues": { "manager": {"name": "Jack", "age": 33}, "subordinate": {"name": "Lucy", "age": 21} } } with open('people.json', 'w') as f: json.dump(data, f) # Extract a specific element with open('people.json') as data_file: ivans_age = next(JsonSlicer(data_file, ('friends', 1, 'age'))) print(f"Ivan's age: {ivans_age}") # Expected: Ivan's age: 26 # Iterate over a collection using wildcards (None) with open('people.json') as data_file: print("\nFriends:") for person in JsonSlicer(data_file, ('friends', None)): print(person) # Expected: {'name': 'John', 'age': 31}, {'name': 'Ivan', 'age': 26} # Iterate over different types of collections at once with open('people.json') as data_file: print("\nAll people:") for person in JsonSlicer(data_file, (None, None)): print(person) # Expected: all 4 people objects # Clean up the dummy file os.remove('people.json')

Debug

Known issues

gotchaInstallation requires a C++ compiler and `pkg-config` to build the YAJL dependency, which might fail on systems without proper development tools.

fix

Ensure C++ development tools (e.g., `build-essential` on Debian/Ubuntu, Xcode Command Line Tools on macOS) and `pkg-config` are installed before attempting to `pip install jsonslicer`.

affects: All versions

gotchaFor optimal performance, especially with very large JSON files, `JsonSlicer` prefers binary input. Using text input (e.g., a file opened without `rb` mode) incurs a ~3% performance overhead due to unnecessary encoding/decoding.

fix

When reading from a file, open it in binary read mode: `with open('file.json', 'rb') as data: JsonSlicer(data, ...)`.

affects: All versions

gotchaWhile generally faster than pure Python JSON parsers, `jsonslicer` can sometimes be slower than `ijson` with its C backend for very deep data structures if many intermediate C values need to be converted to Python objects.

fix

Benchmark against `ijson` (with `yajl2_c` backend if available) for specific deep parsing scenarios to determine the optimal library. Consider the complexity of the extraction path vs. the volume of data to be converted to Python objects.

affects: All versions

deprecatedVersions prior to 0.1.5 might have compatibility issues with Python 3.8 and newer due to a compatibility fix introduced in that release.

fix

Upgrade to `jsonslicer` version 0.1.5 or newer: `pip install --upgrade jsonslicer`.

affects: <0.1.5

gotchaThe `yajl_verbose_errors` flag can be set to enable more detailed error messages, which might be helpful for debugging malformed JSON, as the default error verbosity might be limited.

fix

When initializing `JsonSlicer`, pass `yajl_verbose_errors=True` to get detailed error messages including the JSON text and character where the error occurred. E.g., `JsonSlicer(data_file, path, yajl_verbose_errors=True)`.

affects: All versions

Upgrade

Version history

0.1.8latest on PyPI · released Oct 25, 2022

Audit

Dependencies

yajlrequiredCore C library dependency for JSON parsing. Version 2.0.3+ required.

pkg-configrequiredBuild-time dependency for locating YAJL.

C++ compilerrequiredBuild-time dependency as the core module is written in C.

Agent activity

8 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/AMDmi3/jsonslicer ↗

packagehttps://pypi.org/project/jsonslicer/ ↗