Welcome to Data-Extractor’s documentation!¶

Combine XPath, CSS Selectors and JSONPath for Web data extracting.

Quickstarts¶

Installation¶

Install the stable version from PYPI.

pip install "data-extractor[jsonpath-extractor]"  # for extracting JSON data
pip install "data-extractor[lxml]"  # for extracting HTML data

Or install the latest version from Github.

pip install "data-extractor[jsonpath-extractor] @ git+https://github.com/linw1995/data_extractor.git@master"

Extract JSON data¶

Currently supports to extract JSON data with below optional dependencies

install one dependency of them to extract JSON data.

Extract HTML(XML) data¶

Currently supports to extract HTML(XML) data with below optional dependencies

lxml for using XPath
cssselect for using CSS-Selectors

Usage¶

from data_extractor import Field, Item, JSONExtractor


class Count(Item):
    followings = Field(JSONExtractor("countFollowings"))
    fans = Field(JSONExtractor("countFans"))


class User(Item):
    name_ = Field(JSONExtractor("name"), name="name")
    age = Field(JSONExtractor("age"), default=17)
    count = Count()


assert User(JSONExtractor("data.users[*]"), is_many=True).extract(
    {
        "data": {
            "users": [
                {
                    "name": "john",
                    "age": 19,
                    "countFollowings": 14,
                    "countFans": 212,
                },
                {
                    "name": "jack",
                    "description": "",
                    "countFollowings": 54,
                    "countFans": 312,
                },
            ]
        }
    }
) == [
    {"name": "john", "age": 19, "count": {"followings": 14, "fans": 212}},
    {"name": "jack", "age": 17, "count": {"followings": 54, "fans": 312}},
]

Changelog¶

Unreleased¶

Feature

Generic extractor with convertor (#83)
mypy plugin for type annotation of extracting result (#83)

v0.10.2¶

Build

upgrade jsonpath-extractor to v0.8.0

Contributing¶

Environment Setup¶

Clone the source codes from Github.

git clone https://github.com/linw1995/data_extractor.git
cd data_extractor

Setup the development environment. Please make sure you install the pdm, pre-commit and nox CLIs in your environment.

make init
make PYTHON=3.7 init  # for specific python version

Linting¶

Use pre-commit for installing linters to ensure a good code style.

make pre-commit

Run linters. Some linters run via CLI nox, so make sure you install it.

make check-all

Testing¶

Run quick tests.

make

Run quick tests with verbose.

make vtest

Run tests with coverage. Testing in multiple Python environments is powered by CLI nox.

make cov