downloader-py3

Download URLs using a compressed disk cache and a random throttling interval.


Keywords
downloader, dwonloader-py3
License
MIT
Install
pip install downloader-py3==1.0.2

Documentation

Each Downloader maintains an sqlite3-based disk cache that utilizes zlib
compression. Network requests are only made if the cached version of the
resource has an age larger or equal to the stale_after value provided by the
programmer.

Between network requests a throttling interval needs to elapse. This throttling
interval is randomly chosen, but lies within the throttle_bounds defined by the
programmer.

HTML resources can be parsed using lxml and in this case an lxml ElementTree is
returned instead of a file object, with the links rewritten to be absolute in
order to facilitate following them. The parsing is done leniently in order to
not fail when invalid HTML is encountered.

The programmer can also supply a function that decides whether the server has
banned the client (possibly by examining the returned resource). In this case
an exception will be raised.

Downloader's features make it ideal for writing scrapers, as it can keep its
network footprint small (due to the cache) and irregular (due to the random
throttling interval).

To install, simply run:

python setup.py install

For documentation, after installing, run:

python -m pydoc downloader