feat: solution for 'Повторный экзамен #2: Граф с рефлексией на код'

README.md

@@ -7,11 +7,15 @@
 EN
 Повторный экзамен #2: Граф с рефлексией на код
 Зачёт
-Версия 1
+Версия 2
 Дедлайн сдачи: 31.08.2026
 
 В работе
 
+Требуется доработка
+
+В работе не обнаружено использования ключевых технологий, указанных в условии задания. Для успешной сдачи необходимо добавить соответствующие импорты и примеры кода.
+
 Редактирование ответа
 
 Заполните ответ и отправьте работу на проверку преподавателю.
@@ -20,15 +24,5 @@ EN
 Текст
 Ссылка
 Файлы
-Текст ответа
+Ссылка (URL)
-Прикреплённые файлы
+Прикреплённ
-Загрузить файл
-Отправить на проверку
-Отменить
-
-Задание
-
-Практическое задание: LangGraph с рефлексией на код
-Цель
-
-Реализовать LangGraph-агента, который берёт функцию на Python и п

requirements.txt

@@ -0,0 +1,4 @@
+langgraph
+langchain-openai
+langchain-core
+python-dotenv

src/cli.py

@@ -0,0 +1,41 @@
+import os
+from src.graph import build_graph
+from src.state import CodeReviewState
+
+def main():
+    # Example function to review
+    def sort_numbers(arr):
+        return sorted(arr)
+
+    # Get source code as string
+    import inspect
+    code_str = inspect.getsource(sort_numbers)
+
+    # Initial state
+    state: CodeReviewState = {
+        "code": code_str,
+        "draft_review": None,
+        "criteria_scores": None,
+        "weakest_criterion": None,
+        "verdict": None,
+        "round": 0,
+        "max_rounds": 2,
+    }
+
+    graph = build_graph()
+    # Run the graph
+    final_state = graph.invoke(state)
+
+    # Print results
+    print("\n=== Initial Draft Review ===")
+    print(final_state["draft_review"])
+    print("\n=== Scores ===")
+    for k, v in final_state["criteria_scores"].items():
+        print(f"{k}: {v}")
+    print("\n=== Verdict ===")
+    print(final_state["verdict"])
+    print("\n=== Final Review (after rewrites if any) ===")
+    print(final_state["draft_review"])
+
+if __name__ == "__main__":
+    main()

src/graph.py

@@ -0,0 +1,24 @@
+from langgraph.graph import StateGraph, END, START
+from src.state import CodeReviewState
+from src.nodes import draft_review, reflect, rewrite
+
+def build_graph() -> StateGraph:
+    graph = StateGraph(CodeReviewState)
+
+    # Add nodes
+    graph.add_node("draft_review", draft_review)
+    graph.add_node("reflect", reflect)
+    graph.add_node("rewrite", rewrite)
+
+    # Define transitions
+    graph.set_entry_point("draft_review")
+    graph.add_edge("draft_review", "reflect")
+    graph.add_conditional_edges(
+        "reflect",
+        lambda state: (
+            "rewrite" if state["verdict"] == "needs_revision" and state["round"] < state["max_rounds"] else END
+        ),
+    )
+    graph.add_edge("rewrite", "reflect")
+
+    return graph

src/main.py

@@ -0,0 +1,4 @@
+from src.cli import main
+
+if __name__ == "__main__":
+    main()

src/nodes.py

@@ -0,0 +1,80 @@
+from typing import Dict, Any
+from langgraph.graph import StateGraph, END, START
+from langchain_openai import ChatOpenAI
+from langchain_core.prompts import ChatPromptTemplate, MessagesPlaceholder
+from langchain_core.output_parsers import JsonOutputParser
+from src.state import CodeReviewState
+
+# LLM instance
+llm = ChatOpenAI(temperature=0, model="gpt-4o-mini")
+
+# Prompt for draft review
+draft_prompt = ChatPromptTemplate.from_messages(
+    [
+        ("system", "You are a senior code reviewer. Provide a concise review with 3-6 bullet points."),
+        ("human", "Here is the Python function:\n\n{code}\n\nWrite your review:"),
+    ]
+)
+
+# Prompt for reflection (scoring)
+reflect_prompt = ChatPromptTemplate.from_messages(
+    [
+        ("system", "You are a code quality critic. Evaluate the following review on four criteria: PEP8, type hints, edge cases, naming. Provide scores 0-10 and a verdict 'ok' or 'needs_revision'. Output JSON with keys: pep8, type_hints, edge_cases, naming, verdict."),
+        ("human", "Review:\n\n{draft_review}\n\nScores:"),
+    ]
+)
+
+# Prompt for rewrite
+rewrite_prompt = ChatPromptTemplate.from_messages(
+    [
+        ("system", "You are a code reviewer tasked with improving the weakest part of the review. Keep other points unchanged."),
+        ("human", "Weakest criterion: {weakest_criterion}\n\nOriginal review:\n\n{draft_review}\n\nRewrite the section addressing the weakest criterion:"),
+    ]
+)
+
+# Output parser for reflection
+json_parser = JsonOutputParser()
+
+def draft_review(state: CodeReviewState) -> CodeReviewState:
+    """Generate initial draft review."""
+    messages = draft_prompt.format_messages(code=state["code"])
+    review = llm.invoke(messages).content
+    state["draft_review"] = review.strip()
+    state["round"] = 0
+    return state
+
+def reflect(state: CodeReviewState) -> CodeReviewState:
+    """Score the draft review."""
+    messages = reflect_prompt.format_messages(draft_review=state["draft_review"])
+    raw_output = llm.invoke(messages).content
+    try:
+        scores = json_parser.parse(raw_output)
+    except Exception as e:
+        # Fallback: if parsing fails, set default scores
+        scores = {
+            "pep8": 0,
+            "type_hints": 0,
+            "edge_cases": 0,
+            "naming": 0,
+            "verdict": "needs_revision",
+        }
+    # Determine weakest criterion
+    criteria = ["pep8", "type_hints", "edge_cases", "naming"]
+    weakest = min(criteria, key=lambda c: scores[c])
+    state["criteria_scores"] = {c: int(scores[c]) for c in criteria}
+    state["weakest_criterion"] = weakest
+    state["verdict"] = scores["verdict"]
+    return state
+
+def rewrite(state: CodeReviewState) -> CodeReviewState:
+    """Rewrite the weakest part of the review."""
+    messages = rewrite_prompt.format_messages(
+        weakest_criterion=state["weakest_criterion"],
+        draft_review=state["draft_review"],
+    )
+    rewritten = llm.invoke(messages).content
+    # Replace the section related to weakest criterion
+    # For simplicity, we just append the rewritten part to the original review
+    state["draft_review"] = f"{state['draft_review']}\n\nImproved {state['weakest_criterion']} section:\n{rewritten.strip()}"
+    state["round"] += 1
+    return state

src/state.py

@@ -1,10 +1,10 @@
-from typing import TypedDict, Dict
+from typing import TypedDict, Dict, Any
 
 class CodeReviewState(TypedDict):
     code: str
-    draft_review: str
+    draft_review: str | None
-    criteria_scores: Dict[str, int]
+    criteria_scores: Dict[str, int] | None
-    weakest_criterion: str
+    weakest_criterion: str | None
-    verdict: str
+    verdict: str | None  # "ok" | "needs_revision"
     round: int
     max_rounds: int