Python script to expand file contents with placeholders

expand.py

"""
Example usage:
python3.10 expand.py template.md > expanded.md

This will expand all {file_path} placeholders in template.md with the actual file contents
and write the result to expanded.md



```template.md
You will be given several files, your goal is to convert the implementation.

<source_implementation>
{/path/to/source/file.py}
</source_implementation>

<target_framework>
{/path/to/target/framework/example.py}
</target_framework>

<reference_implementation>
{/path/to/reference/implementation.py}
</reference_implementation>
```
"""
import re
import os
import fire



class PlaceholderEnumerator:
    def __call__(self, match):
        # match.group(1) is the content inside the braces
        content = match.group(1) if match.group(1) else ""

        assert os.path.isfile(content), f"File {content} does not exist"
        with open(content, 'r', encoding='utf-8') as f:
            file_content = f.read()
        return file_content

def replace_w_enumerator(s):
    enumerator = PlaceholderEnumerator()
    result = re.sub(r"\{([^}]*)\}", enumerator, s)
    return result

def expand_file(file_path):
    with open(file_path, 'r') as file:
        content = file.read()
    print(replace_w_enumerator(content))



# python3.10 expand.py bla.md > prompt.md
if __name__ == "__main__":
    fire.Fire(expand_file)