rohitg00/ai-engineering-from-scratch · error · ValueError

Missing variables for {pattern_name}: {missing}

Error message

Missing variables for {pattern_name}: {missing}

What it means

Error "Missing variables for {pattern_name}: {missing}" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at phases/11-llm-engineering/01-prompt-engineering/code/prompt_engineering.py:177

        "context_window": 1_000_000,
    },
    "gemini-1.5-pro": {
        "provider": "google",
        "model": "gemini-2.5-pro",
        "max_tokens": 2048,
        "context_window": 1_000_000,
    },
}


def build_prompt(pattern_name, variables, system_override=None):
    pattern = PROMPT_PATTERNS.get(pattern_name)
    if not pattern:
        raise ValueError(f"Unknown pattern: {pattern_name}. Available: {list(PROMPT_PATTERNS.keys())}")

    missing = [v for v in pattern["variables"] if v not in variables]
    if missing:
        raise ValueError(f"Missing variables for {pattern_name}: {missing}")

    rendered = pattern["template"].format(**variables)
    system = system_override or f"You are an AI assistant using the {pattern['name']}."

    return {
        "system": system,
        "user": rendered,
        "temperature": pattern["temperature"],
        "pattern": pattern_name,
        "metadata": {
            "description": pattern["description"],
            "variables_used": list(variables.keys()),
        },
    }


def build_multi_turn(pattern_name, turns, system_override=None):
    pattern = PROMPT_PATTERNS.get(pattern_name)

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at phases/11-llm-engineering/01-prompt-engineering/code/prompt_engineering.py:177 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rohitg00/ai-engineering-from-scratch@39ea8a1c6d (2026-08-26). Data as JSON: /api/errors/d0e6af713def6ee2. Report an issue: GitHub.