data-services-helpers

A module containing classes and functions that The Sensible Code Company's Data Services often uses.

Installation

For the current release:

pip install dshelpers

Usage

batch_processor

with batch_processor(callback_function(), batch_size=2000) as b:
    # loop to make rows here
    b.push(row)

Here, push on the batch_processor queues items in a list. When the context manager is exited, calls the callback_function with the list of items.

Often used to bundle multiple calls to scraperwiki.sqlite.save when saving data to a database.

install_cache

install_cache(expire_after=12 * 3600, cache_post=False)

For installing a requests_cache; requires the requests-cache package.

expire_after is the cache expiry time in seconds.

cache_post defines if HTTP POST requests should be cached as well.

download_url

download_url(url, back_off=True, **kwargs)

Retrieve the content of url, by default using requests.request('GET', url), and return a file-like object. If back_off=True, then this will retry (with backoff) on failure; otherwise, only one attempt is made. Returns the response.content as a StringIO object.

The **kwargs can be arguments that requests recognises, e.g. method or headers.

request_url

request_url(url, back_off=True, **kwargs)

As download_url, but returns the response object.

Tests

Run with pytest dshelpers.py.