SDV - Add a Metadata.detect_from_dataframe function (#2222)

sdv/metadata/metadata.py

@@ -2,6 +2,8 @@
 
 import warnings
 
+import pandas as pd
+
 from sdv.metadata.errors import InvalidMetadataError
 from sdv.metadata.multi_table import MultiTableMetadata
 from sdv.metadata.single_table import SingleTableMetadata
@@ -51,6 +53,28 @@ def load_from_dict(cls, metadata_dict, single_table_name=None):
         instance._set_metadata_dict(metadata_dict, single_table_name)
         return instance
 
+    @classmethod
+    def detect_from_dataframe(cls, data, table_name=DEFAULT_SINGLE_TABLE_NAME):
+        """Detect the metadata for a DataFrame.
+
+        This method automatically detects the ``sdtypes`` for the given ``pandas.DataFrame``.
+        All data column names are converted to strings.
+
+        Args:
+            data (pandas.DataFrame):
+                Dictionary of table names to dataframes.
+
+        Returns:
+            Metadata:
+                A new metadata object with the sdtypes detected from the data.
+        """
+        if not isinstance(data, pd.DataFrame):
+            raise ValueError('The provided data must be a pandas DataFrame object.')
+
+        metadata = Metadata()
+        metadata.detect_table_from_dataframe(table_name, data)
+        return metadata
+
     def _set_metadata_dict(self, metadata, single_table_name=None):
         """Set a ``metadata`` dictionary to the current instance.
 

tests/integration/metadata/test_metadata.py

@@ -85,7 +85,7 @@ def test_detect_from_dataframes_multi_table():
     assert metadata.to_dict() == expected_metadata
 
 
-def test_detect_from_data_frames_single_table():
+def test_detect_from_dataframes_single_table():
     """Test the ``detect_from_dataframes`` method works with a single table."""
     # Setup
     data, _ = download_demo(modality='multi_table', dataset_name='fake_hotels')
@@ -116,6 +116,36 @@ def test_detect_from_data_frames_single_table():
     assert metadata.to_dict() == expected_metadata
 
 
+def test_detect_from_dataframe():
+    """Test that a single table can be detected as a DataFrame."""
+    # Setup
+    data, _ = download_demo(modality='multi_table', dataset_name='fake_hotels')
+
+    metadata = Metadata.detect_from_dataframe(data['hotels'])
+
+    # Run
+    metadata.validate()
+
+    # Assert
+    expected_metadata = {
+        'METADATA_SPEC_VERSION': 'V1',
+        'tables': {
+            DEFAULT_TABLE_NAME: {
+                'columns': {
+                    'hotel_id': {'sdtype': 'id'},
+                    'city': {'sdtype': 'city', 'pii': True},
+                    'state': {'sdtype': 'administrative_unit', 'pii': True},
+                    'rating': {'sdtype': 'numerical'},
+                    'classification': {'sdtype': 'unknown', 'pii': True},
+                },
+                'primary_key': 'hotel_id',
+            }
+        },
+        'relationships': [],
+    }
+    assert metadata.to_dict() == expected_metadata
+
+
 def test_detect_from_csvs(tmp_path):
     """Test the ``detect_from_csvs`` method."""
     # Setup

tests/unit/metadata/test_metadata.py

@@ -1,9 +1,10 @@
-from unittest.mock import patch
+from unittest.mock import Mock, patch
 
+import pandas as pd
 import pytest
 
 from sdv.metadata.metadata import Metadata
-from tests.utils import get_multi_table_data, get_multi_table_metadata
+from tests.utils import DataFrameMatcher, get_multi_table_data, get_multi_table_metadata
 
 
 class TestMetadataClass:
@@ -537,3 +538,29 @@ def test_validate_data_no_relationships(self):
         # Run and Assert
         metadata.validate_data(data)
         assert metadata.METADATA_SPEC_VERSION == 'V1'
+
+    @patch('sdv.metadata.metadata.Metadata')
+    def test_detect_from_dataframe(self, mock_metadata):
+        """Test that the method calls the detection method and returns the metadata.
+
+        Expected to call ``detect_table_from_dataframe`` for the dataframe.
+        """
+        # Setup
+        mock_metadata.detect_table_from_dataframe = Mock()
+        data = pd.DataFrame()
+
+        # Run
+        metadata = Metadata.detect_from_dataframe(data)
+
+        # Assert
+        mock_metadata.return_value.detect_table_from_dataframe.assert_any_call(
+            Metadata.DEFAULT_SINGLE_TABLE_NAME, DataFrameMatcher(data)
+        )
+        assert metadata == mock_metadata.return_value
+
+    def test_detect_from_dataframe_raises_error_if_not_dataframe(self):
+        """Test that the method raises an error if data isn't a DataFrame."""
+        # Run and assert
+        expected_message = 'The provided data must be a pandas DataFrame object.'
+        with pytest.raises(ValueError, match=expected_message):
+            Metadata.detect_from_dataframe(Mock())