Move flatten_list util function into feature_discovery

docs/source/release_notes.rst

@@ -7,11 +7,12 @@ Future Release
 ==============
     * Enhancements
     * Fixes
+        * Move ``flatten_list`` util function into ``feature_discovery`` module to fix import bug (:pr:`2702`)
     * Changes
-        * Temporarily restrict Dask version :pr:`2694`
+        * Temporarily restrict Dask version (:pr:`2694`)
     * Documentation Changes
     * Testing Changes
-        * Fix serialization test to work with pytest 8.1.1 :pr:`2694`
+        * Fix serialization test to work with pytest 8.1.1 (:pr:`2694`)
 
     Thanks to the following people for contributing to this release:
     :user:`thehomebrewnerd`

featuretools/feature_discovery/feature_discovery.py

@@ -9,9 +9,8 @@
 
 from featuretools.feature_discovery.FeatureCollection import FeatureCollection
 from featuretools.feature_discovery.LiteFeature import LiteFeature
-from featuretools.feature_discovery.utils import column_schema_to_keys
+from featuretools.feature_discovery.utils import column_schema_to_keys, flatten_list
 from featuretools.primitives.base.primitive_base import PrimitiveBase
-from featuretools.tests.testing_utils.generate_fake_dataframe import flatten_list
 
 
 def _index_column_set(column_set: List[ColumnSchema]) -> List[Tuple[str, int]]:

featuretools/feature_discovery/utils.py

@@ -75,3 +75,7 @@ def get_primitive_return_type(primitive: PrimitiveBase) -> ColumnSchema:
     if isinstance(return_type, list):
         return_type = return_type[0]
     return return_type
+
+
+def flatten_list(nested_list):
+    return [item for sublist in nested_list for item in sublist]

featuretools/tests/testing_utils/generate_fake_dataframe.py

@@ -6,6 +6,8 @@
 import woodwork.type_sys.type_system as ww_type_system
 from woodwork import logical_types
 
+from featuretools.feature_discovery.utils import flatten_list
+
 logical_type_mapping = {
     logical_types.Boolean.__name__: [True, False],
     logical_types.BooleanNullable.__name__: [True, False, pd.NA],
@@ -32,10 +34,6 @@
 }
 
 
-def flatten_list(nested_list):
-    return [item for sublist in nested_list for item in sublist]
-
-
 def generate_fake_dataframe(
     col_defs=[("f_1", "Numeric"), ("f_2", "Datetime", "time_index")],
     n_rows=10,

pyproject.toml

@@ -158,8 +158,8 @@ filterwarnings = [
 [tool.ruff]
 line-length = 88
 target-version = "py311"
-ignore = ["E501"]
-select = [
+lint.ignore = ["E501"]
+lint.select = [
     # Pyflakes
     "F",
     # Pycodestyle
@@ -170,10 +170,10 @@ select = [
 ]
 src = ["featuretools"]
 
-[tool.ruff.per-file-ignores]
+[tool.ruff.lint.per-file-ignores]
 "__init__.py" = ["E402", "F401", "I001", "E501"]
 
-[tool.ruff.isort]
+[tool.ruff.lint.isort]
 known-first-party = ["featuretools"]
 
 [tool.coverage.run]