Add ACRE(Abstract Causal REasoning Beyond Covariation) python generators (#199)

* Add acre python generators
* acre: improved prompt & formatting of examples, support arbitrary sizes

---------

Co-authored-by: Andreas Koepf <andreas.koepf@provisio.com>

tests/test_acre.py

@@ -0,0 +1,65 @@
+import pytest
+
+from reasoning_gym.induction.acre.acre import ACREDataset, ACREDatasetConfig
+
+
+def test_acre_config_validation():
+    """Test that config validation works"""
+    config = ACREDatasetConfig(size=-1)
+    with pytest.raises(AssertionError):
+        config.validate()
+
+
+def test_acre_dataset_deterministic():
+    """Test that dataset generates same items with same seed"""
+    config = ACREDatasetConfig(seed=42, size=10)
+    dataset1 = ACREDataset(config)
+    dataset2 = ACREDataset(config)
+
+    for i in range(len(dataset1)):
+        assert dataset1[i] == dataset2[i]
+
+
+def test_acre_items():
+    """Test basic properties of generated items"""
+    config = ACREDatasetConfig(size=50, seed=42)
+    dataset = ACREDataset(config)
+
+    for i in range(len(dataset)):
+        item = dataset[i]
+        assert isinstance(item, dict)
+        assert "question" in item
+        assert "answer" in item
+        assert isinstance(item["question"], str)
+        assert isinstance(item["answer"], str)
+
+
+def test_acre_iteration():
+    """Test that iteration respects dataset size"""
+    config = ACREDatasetConfig(size=10, seed=42)  # Small size for testing
+    dataset = ACREDataset(config)
+
+    # Test manual iteration
+    items = []
+    for item in dataset:
+        items.append(item)
+    assert len(items) == config.size, "Iterator should yield exactly size items"
+
+    # Test list conversion
+    items = list(dataset)
+    assert len(items) == config.size, "Iterator should yield exactly size items"
+
+    # Test multiple iterations
+    first_items = list(dataset)
+    second_items = list(dataset)
+    assert first_items == second_items, "Multiple iterations should yield same items"
+
+
+def test_acre_questions_generator():
+    """Test question generator loading and access"""
+    config = ACREDatasetConfig(size=10, seed=42)
+    dataset = ACREDataset(config)
+
+    # Test properties of questions
+    assert isinstance(dataset.questions, list)
+    assert len(dataset.questions) > 0