tempest

Syntax-independent text templating library

Easily embed literal python code into any file.

Features:

• Configurable open/close delimiters
• Works with any language
• It's just more python

Big Scary Security Warning

This library will execute arbitrary code contained in the template. Do not allow untrusted templates to be executed.

Install

pip install tempest-fmt

Example

Template

# This is a markdown file

Hello my name is {name=}

My friends are:
{for f in friends:}
    - {f=}

{divisor = 2}
{for i in range(5):}
    {if i % divisor == 0:}
        Did you know {i=} is divisible by {divisor=}

I can even evaluate stuff: {len(name)=}

Python Implementation

import tempest

t = tempest.parse_template_file("myTemplate.md", "{", "}")

values = {
    "name": "Jimmy",
    "friends": ["Carl", "Steve", "Greg"],
}

with open("output.md", mode='w') as f:
    t.generate(f, value)

Output file

# This is a markdown file

Hello my name is Jimmy

My friends are:
- Carl
- Steve
- Greg

Did you know 0 is divisible by 2
Did you know 2 is divisible by 2
Did you know 4 is divisible by 2

I can even evaluate stuff: 5

Syntax specifics

For simplicity, we will assume the delimiters to be { }
All python statements will be contained within the delimiters, any text outside will be considered raw text.

Statements of the form {<expr>=} will be evaluated as str(<expr>) and directly inserted into the text.
All other statements will be considered logical statements. Such statements must follow indentation rules for python and should have no raw text on the line. Any statements following will have indentation stripped, this includes raw text (extra whitespace after the expected indentation is left as-is).

Indentation is important
Leading spaces replaced with dots for this example

{for x in range(3):}
....- {x}

My next thing

Will produce

- 0
- 1
- 2

My next thing

Compared to

{for x in range(3):}
....- {x}
....

My next thing

Will produce

- 0

- 1

- 2

My next thing