imgix-python is a client library for generating image URLs with imgix.

• Installation
• Usage
  • Signed URLs
  • Srcset Generation
  • Usage with UTF-8
• Testing

Installation

pip install imgix

Usage

To begin creating imgix URLs programmatically, import the imgix library and create a URL builder. The URL builder can be reused to create URLs for any images on the domains it is provided.

import imgix

builder = imgix.UrlBuilder("demos.imgix.net")
print builder.create_url("/bridge.png", {'w': 100, 'h': 100})

# Prints out:
# http://demos.imgix.net/bridge.png?h=100&w=100

For HTTPS support, specify the HTTPS flag like so:

import imgix

builder = imgix.UrlBuilder("demos.imgix.net", use_https=True)
print builder.create_url("/bridge.png", {'w': 100, 'h': 100})

# Prints out:
# https://demos.imgix.net/bridge.png?h=100&w=100

Signed URLs

To produce a signed URL, you must enable secure URLs on your source and then provide your signature key to the URL builder.

import imgix

builder = imgix.UrlBuilder("demos.imgix.net", sign_key="test1234")
print builder.create_url("/bridge.png", {'w': 100, 'h': 100})

# Prints out:
# http://demos.imgix.net/bridge.png?h=100&w=100&s=7370d6e36bb2262e73b19578739af1af

Srcset Generation

The imgix-python package allows for generation of custom srcset attributes, which can be invoked through create_srcset(). By default, the srcset generated will allow for responsive size switching by building a list of image-width mappings.

builder = imgix.UrlBuilder("demos.imgix.net", sign_key="my-token", include_library_param=False)
srcset = builder.create_srcset("image.png")
print srcset

Will produce the following attribute value, which can then be served to the client:

https://demos.imgix.net/image.png?w=100&s=e415797545a77a9d2842dedcfe539c9a 100w,
https://demos.imgix.net/image.png?w=116&s=b2da46f5c23ef13d5da30f0a4545f33f 116w,
https://demos.imgix.net/image.png?w=134&s=b61422dead929f893c04b8ff839bb088 134w,
                                        ...
https://demos.imgix.net/image.png?w=7400&s=ad671301ed4663c3ce6e84cb646acb96 7400w,
https://demos.imgix.net/image.png?w=8192&s=a0fed46e2bbcc70ded13dc629aee5398 8192w

In cases where enough information is provided about an image's dimensions, create_srcset() will instead build a srcset that will allow for an image to be served at different resolutions. The parameters taken into consideration when determining if an image is fixed-width are w, h, and ar. By invoking create_srcset() with either a width or the height and aspect ratio (along with fit=crop, typically) provided, a different srcset will be generated for a fixed-size image instead.

builder = imgix.UrlBuilder("demos.imgix.net", sign_key="my-token", include_library_param=False)
srcset = builder.create_srcset("image.png", {'h':800, 'ar':'3:2', 'fit':'crop'})
print srcset

Will produce the following attribute value:

https://demos.imgix.net/image.png?ar=3%3A2&dpr=1&fit=crop&h=800&s=6cf5c443d1eb98bc3d96ea569fcef088 1x,
https://demos.imgix.net/image.png?ar=3%3A2&dpr=2&fit=crop&h=800&s=d60a61a5f34545922bd8dff4e53a0555 2x,
https://demos.imgix.net/image.png?ar=3%3A2&dpr=3&fit=crop&h=800&s=590f96aa426f8589eb7e449ebbeb66e7 3x,
https://demos.imgix.net/image.png?ar=3%3A2&dpr=4&fit=crop&h=800&s=c89c2fd3148957647e86cfc32ba20517 4x,
https://demos.imgix.net/image.png?ar=3%3A2&dpr=5&fit=crop&h=800&s=3d73af69d78d49eef0f81b4b5d718a2c 5x

For more information to better understand srcset, we highly recommend Eric Portis' "Srcset and sizes" article which goes into depth about the subject.

Usage with UTF-8

For usage with non-ASCII characters, please be sure to that your project's source files specify UTF-8 encoding:

# -*- coding: utf-8 -*-

If you don't add this encoding, and you have an image with name for example 'tiburón.jpeg', you will get the following error trying to run your script:

SyntaxError: Non-ASCII character '***' in file test.py on line 6, but no encoding declared; see http://www.python.org/peps/pep-0263.html for details

Testing

Run the following to execute the project's tests and code linter:

tox

Changelog

3.1.2 (2019-03-11)

• Fix Python 2/3 compatibility issues (#57)

3.1.1 (2019-08-22)

• fix: include dpr parameter when generating fixed-width srcset (#50)

3.1.0 (2019-08-22)

• feat: add srcset generation (#48)
• build(tox): improve code coverage reporting; parallelize testing (#49)

3.0.0 (2019-06-07)

• fix: remove deprecated domain sharding functionality (#44)
• fix: remove deprecated [opts]{.title-ref} parameter (#46)
• fix: remove deprecated [sign_with_library_version]{.title-ref} parameter (#47)

2.3.0 (2019-06-06)

• feat: deprecate [domains]{.title-ref} in favor of [domain]{.title-ref} (#45)

2.2.0 (2019-05-07)

• deprecate domain sharding (#41)(#42)

2.1.0 (2019-02-13)

• Domain validation added during [UrlBuilder]{.title-ref} initialization
• [sign_with_library_version]{.title-ref} parameter from [UrlBuilder]{.title-ref} deprecated in favor of [include_library_param]{.title-ref}.

2.0.0 (2018-08-08)

• [UrlBuilder]{.title-ref}'s [sign_mode]{.title-ref} argument removed
• [opts]{.title-ref} parameter from [UrlBuilder.create_url]{.title-ref} deprecated in favor of [params]{.title-ref}.

1.2.0 (2018-06-20)

• [sign_mode]{.title-ref} argument deprecated
• License corrected to BSD-2-Clause.
• Docstrings added to classes and methods.

1.1.2 (2016-06-30)

• Proper encodeURIComponent-style URL encoding for web proxy sources. See #21 for more information.

1.1.0 (2016-02-26)

• Added automatic Base64 encoding for all Base64 variant parameters.
• Properly encoding all query keys and values.

1.0.0 (2016-01-15)

• Change UrlBuilder#create_url to accept dict instead of kwargs. This fixes an issue with reserved words that are also imgix params potentially causing errors.

0.2.1 (2016-01-15)

• Fixed a bug where any passed params that were falsy would not be passed through to imgix.

0.2.0 (2015-06-15)

• Introduces defaulting to HTTPS on all requests, per the imgix-blueprint.

0.1.0 (2015-06-11)

• Includes new functionality to sign every URL with an ixlib parameter for diagnostic purposes.

0.0.4 (2015-06-10)

• New README note about publishing packages