ai-agent-book 精选快照（<2MB 代码与文档，来自 github.com/bojieli/ai-agent-book）

chapter7/elo-leaderboard/tests/test_ch6_compare_win_rates_empty.py

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+"""Regression test for compare_win_rates when comparisons list is empty."""
+import numpy as np
+import pandas as pd
+from elo_rating import EloRatingSystem
+from leaderboard import compare_win_rates
+
+
+def test_compare_win_rates_empty_has_required_columns():
+    """compare_win_rates must return a DataFrame with required columns when no valid comparisons exist."""
+    elo = EloRatingSystem()
+    empirical_df = pd.DataFrame(np.nan, index=["model_a", "model_b"], columns=["model_a", "model_b"])
+    df_comp = compare_win_rates(elo, empirical_df)
+    assert list(df_comp.columns) == ["model_a", "model_b", "empirical", "predicted", "error"]
+    assert len(df_comp) == 0
+    # Accessing columns on empty result must not raise KeyError
+    assert "error" in df_comp
+    assert df_comp["error"].empty