Tempyl is a super simple python-based templating tool. It's super easy to use with LaTeX and HTML, but can be used for whatever you want.

Download tempyl.py and run it as follows:

python3 tempyl.py template_file data_file output_file

template.html

<h1>$article_name</h1>

data.json

{
  "article_name": "My favorite restauraunt!"
}

output.html

<h1>My favorite restaurant!</h1>

Use data scopes access JSON sub-objects.

template.html

## article
<h1>$name</h1>
##

data.json

{
  "article": {
    "name": "Why pasta tastes good."
  }
}

output.html

<h1>Why pasta tastes good.</h1>

Iterate over JSON lists and reuse part of a template.

template.html

<h1>$title</h1>
## items
<h2>$name</h2>
<p>$desc</p>
##

data.json

{
  "title": "A list of things",
  "items": [
    {
      "name": "Thing A",
      "desc": "Not thing B"
    },
    {
      "name": "Thing B",
      "desc": "Not thing A"
    }
  ]
}

output.html

<h1>A list of things</h1>
<h2>Thing A</h2>
<p>Not thing B</p>
<h2>Thing B</h2>
<p>Not thing A</p>

Use special identifier self for a list of strings. template.txt`

My favorite letters:
## items
  $self
##

Edit list.begin, .separator and .end properties to change how lists are rendered. data.json

{
  "items.begin": "",
  "items.separator": ", ",
  "items.end": ".",
  "items": ["a", "b", "c"]
}

out.txt

My favorite letters: a, b, c.

Disable elements in a list with .disabled. template.txt

## items
  $items.name
##

data.json

{
  "items": [
    { "name": "grape" },
    { ".disabled": true, "name": "apple" },
    { "name": "orange" }
  ]
}

out.txt

  grape
  orange