import re

_PATTERN = re.compile(r"\{\{(\w+)\}\}")

def render(value, context: dict):
    if not isinstance(value, str):
        return value

    def replace(match):
        key = match.group(1)
        return str(context.get(key, ""))

    return _PATTERN.sub(replace, value)


def render_headers(headers: dict, context: dict):
    return {
        k: render(v, context)
        for k, v in headers.items()
    }