Single page linear scrapers

For this example, we will extract content from a pyvideo page. Let us consider the following page.

To generate a skeleton configuration file, use the genconfig command. The primary arguments for the command are the project name and the URL of the base page.

$ scrapple genconfig pyvideo \
> http://pyvideo.org/video/1785/python-for-humans-1

This will create pyvideo.json which will initially look like this -

{

    "scraping": {
        "url": "http://pyvideo.org/video/1785/python-for-humans-1",
        "data": [
            {
                "field": "",
                "attr": "",
                "selector": "",
                "default": ""
            }
        ]
    },
    "project_name": "pyvideo",
    "selector_type": "xpath"

}

You can edit this json file to specify selectors for the various data that you would want to extract from the given page.

For example,

{

    "scraping": {
        "url": "http://pyvideo.org/video/1785/python-for-humans-1",
        "data": [
            {
                "field": "title",
                "attr": "text",
                "selector": "//h3",
                "default": ""
            },
            {
                "field": "speaker_name",
                "attr": "text",
                "selector": "//div[@id='sidebar']//dd[2]//a",
                "default": ""
            },
            {
                "field": "speaker_link",
                "attr": "href",
                "selector": "//div[@id='sidebar']//dd[2]//a",
                "default": ""
            },
            {
                "field": "event_name",
                "attr": "text",
                "selector": "//div[@id='sidebar']//dd[1]//a",
                "default": ""
            },
            {
                "field": "event_link",
                "attr": "href",
                "selector": "//div[@id='sidebar']//dd[1]//a",
                "default": ""
            }
        ]
    },
    "project_name": "pyvideo",
    "selector_type": "xpath"

}

Using this configuration file, you could generate a Python script using scrapple generate or directly run the scraper using scrapple run.

The generate and run commands take two positional arguments - the project name and the output file name.

To generate the Python script -

$ scrapple generate pyvideo talk1

This will create talk1.py, which is the script that can be run to replicate the action of scrapple run.

from __future__ import print_function
import json
import os

from scrapple.selectors.xpath import XpathSelector


def task_pyvideo():
        """
        Script generated using
        `Scrapple <http://scrappleapp.github.io/scrapple>`_
        """
        results = dict()
        results['project'] = "pyvideo"
        results['data'] = list()
        try:
                r0 = dict()
                page0 = XpathSelector(
                "http://pyvideo.org/video/1785/python-for-humans-1"
                )
                r0["title"] = page0.extract_content(
                "//h3", "text", ""
                )
                r0["speaker_name"] = page0.extract_content(
                "//div[@id='sidebar']//dd[2]//a", "text", ""
                )
                r0["speaker_link"] = page0.extract_content(
                "//div[@id='sidebar']//dd[2]//a", "href", ""
                )
                r0["event_name"] = page0.extract_content(
                "//div[@id='sidebar']//dd[1]//a", "text", ""
                )
                r0["event_link"] = page0.extract_content(
                "//div[@id='sidebar']//dd[1]//a", "href", ""
                )
                results['data'].append(r0)
        except KeyboardInterrupt:
                pass
        except Exception as e:
                print(e)
        finally:
                with open(os.path.join(os.getcwd(), 'talk1.json'), 'w') as f:
                        json.dump(results, f)


if __name__ == '__main__':
        task_pyvideo()

To run the scraper -

$ scrapple run pyvideo talk1

This will create talk1.json, which contains the extracted information.

{

    "project": "test1",
    "data": [
        {
            "event_name": "PyCon US 2013",
            "event_link": "/category/33/pycon-us-2013",
            "speaker_link": "/speaker/726/kenneth-reitz",
            "speaker_name": "Kenneth Reitz",
            "title": "Python for Humans"
        }
    ]

}