langfuse-python: simple static method listing prompt template var names

[rhighs]

Describe the feature or potential improvement

It would be nice to have a simple method call like prompt.variables_names() that returns a list of the var names present. For what I was able to see, we could reuse the _compile_template_string static method..

I have some working code already and if you guys agree I could implement this change myself and submit a very short PR.

Bye 👋

Additional information

Example code

@staticmethod
def variables_names(
    content: str
):
    opening = "{{"
    closing = "}}"
    curr_idx = 0
    result_list = []

    while curr_idx < len(content):
        var_start = content.find(opening, curr_idx)
        if var_start == -1:
            break
        var_end = content.find(closing, var_start)
        if var_end == -1:
            break
        variable_name = content[var_start + len(opening) : var_end].strip()
        result_list.append(variable_name)
        curr_idx = var_end + len(closing)

    return result_list

print(get_variables_names("""Explain how {{favorite_pizza_topping}} is linked to sightings of {{ufo_depth_in_meters}} beneath the ocean near {{research_base_name}}.
"""))

Expected output:

['favorite_pizza_topping', 'ufo_depth_in_meters', 'research_base_name']

[marcklingen]

@hassiebp what do you think? seems like a good extension of the prompt management sdk in my view

[hassiebp]

Great idea, @rhighs ! Feel free to submit a PR to support this 👍🏾

[rhighs]

Thank youuuuuuuu

[rhighs]

Reporting the PR here just for ref: langfuse/langfuse-python#1013