silver-nitrate 1.8.1

Python utilities used by the Flickr Foundation

silver-nitrate

This is a collection of Python utilities used by the Flickr Foundation. It allows us to share certain functions and common code across all our projects.

Think of it as a souped-up version of utils.py.

This library is primarily for our use, but the code is fairly generic and may well be useful in other projects. If you want to use it, copy/paste the code (and the associated tests!) into your own project rather than adding a dependency on this library.

Builder's Photo of 2-8-0 Locomotive No 1402 "James Archbald," built in 1930 by the Delaware & Hudson Railroad. Scan of a silver-halide photo print. Photo from Bill Harrison on Flickr.

What's in this library?

This library contains shared functions that are a bit too complicated to copy/paste between different projects.

• nitrate.cassettes -- pytest fixtures for working with vcrpy to record HTTP requests.
• nitrate.flickr_login -- deal with the parts of the Flickr OAuth login process that are the same for every app.
• nitrate.json -- encode/decode JSON in a type-preserving way.
• nitrate.mock_passwords -- a pytest fixture to mock the keyring module.
• nitrate.types -- helpers for validating Python types at runtime.
• nitrate.xml -- type-safe helpers for finding matching elements or text in an XML document.

Why did you pick this name?

We wanted to pick a name that was:

1. More interesting than "utils"
2. Had a connection to photography
3. Wasn't taken on PyPI

Silver nitrate was a key chemical in the early days of photography, especially in the 19th and early 20th centuries.

Photographers would coat glass plates with a mixture of chemicals, including silver nitrate. Because silver nitrate reacts when exposed to light, when you put the plate in a camera and open the shutter, different areas would react differently to create an image on the plate. You could then develop this plate into a photograph.

This code is key to our work at the Flickr Foundation, so it's a fitting name.

Development

If you want to make changes to the library, there are instructions in CONTRIBUTING.md.

License

This project is dual-licensed as Apache-2.0 and MIT.