Add implementation for Amazon Sagemaker Filter

[Abbodavi]

Hello! I've been using this library for a while to test the creation of a liquid template which is then being used by AWS SageMaker GroundTruth to create a custom labeling template. Besides standard Liquid filters Ground Truth offers a few additional filters and recently I've developed some stuff that requires the use of the skip_autoescape filter. However this is currently not present in the library which causes the failure of a few tests.
I had a brief look at the code and I think the implementation shouldn't be particularly hard but since this filter is outside the standard liquid I was wondering if you would be open to their addition or not.

Thanks

[jg-rp]

Hi @Abbodavi,

skip_autoescape looks like Python Liquid's safe filter. You can alias safe as skip_autoescape like this. It's OK to delete safe from self.filters within setup_tags_and_filters too.

"""Alias a Liquid filter example. Require Python Liquid version 2."""
from liquid import Environment

class MyLiquidEnvironment(Environment):
    def setup_tags_and_filters(self, *, extra=False):
        super().setup_tags_and_filters(extra=extra)
        self.filters["skip_autoescape"] = self.filters["safe"]

env = MyLiquidEnvironment(autoescape=True)

template = env.parse(
    "Hello, {{ some_html }}!\n"
    "Hello, {{ some_html | safe }}!\n"
    "Hello, {{ some_html | skip_autoescape }}!"
)

print(template.render(some_html="<p><b>World</b></p>"))

# Hello, &lt;p&gt;&lt;b&gt;World&lt;/b&gt;&lt;/p&gt;!
# Hello, <p><b>World</b></p>!
# Hello, <p><b>World</b></p>!

Note that without autoescape=True, safe has no effect.

In general, I am open to including new filters if they are widely useful. Non-standard filters will usually be disabled by default, and if filters have additional Python dependencies, it might be better to maintain them in a separate project/package. I imagine grant_read_access, for example, would need the Boto3 package, which I would not want to add to Python Liquid, but would make a good custom filter.