Refactor functionality to locations under new mod struct

skbase/_exceptions.py

@@ -6,8 +6,16 @@
 """Custom exceptions used in ``skbase``."""
 from typing import List
 
-__author__: List[str] = ["mloning", "rnkuhns"]
-__all__: List[str] = ["NotFittedError"]
+__author__: List[str] = ["fkiraly", "mloning", "rnkuhns"]
+__all__: List[str] = ["FixtureGenerationError", "NotFittedError"]
+
+
+class FixtureGenerationError(Exception):
+    """Raised when a fixture fails to generate."""
+
+    def __init__(self, fixture_name="", err=None):
+        self.fixture_name = fixture_name
+        super().__init__(f"fixture {fixture_name} failed to generate. {err}")
 
 
 class NotFittedError(ValueError, AttributeError):

skbase/base/_meta.py

@@ -10,6 +10,7 @@
 from typing import List
 
 from skbase.base._base import BaseEstimator
+from skbase.utils._nested_seq import flatten, is_flat, unflatten
 
 __author__: List[str] = ["mloning", "fkiraly"]
 __all__: List[str] = ["BaseMetaEstimator"]
@@ -589,76 +590,6 @@ def _tagchain_is_linked_set(
             self.set_tags(**{mid_tag_name: mid_tag_val_not})
 
 
-def flatten(obj):
-    """Flatten nested list/tuple structure.
-
-    Parameters
-    ----------
-    obj: nested list/tuple structure
-
-    Returns
-    -------
-    list or tuple, tuple if obj was tuple, list otherwise
-        flat iterable, containing non-list/tuple elements in obj in same order as in obj
-
-    Example
-    -------
-    >>> flatten([1, 2, [3, (4, 5)], 6])
-    [1, 2, 3, 4, 5, 6]
-    """
-    if not isinstance(obj, (list, tuple)):
-        return [obj]
-    else:
-        return type(obj)([y for x in obj for y in flatten(x)])
-
-
-def unflatten(obj, template):
-    """Invert flattening, given template for nested list/tuple structure.
-
-    Parameters
-    ----------
-    obj : list or tuple of elements
-    template : nested list/tuple structure
-        number of non-list/tuple elements of obj and template must be equal
-
-    Returns
-    -------
-    rest : list or tuple of elements
-        has element bracketing exactly as `template`
-            and elements in sequence exactly as `obj`
-
-    Example
-    -------
-    >>> unflatten([1, 2, 3, 4, 5, 6], [6, 3, [5, (2, 4)], 1])
-    [1, 2, [3, (4, 5)], 6]
-    """
-    if not isinstance(template, (list, tuple)):
-        return obj[0]
-
-    list_or_tuple = type(template)
-    ls = [unflat_len(x) for x in template]
-    for i in range(1, len(ls)):
-        ls[i] += ls[i - 1]
-    ls = [0] + ls
-
-    res = [unflatten(obj[ls[i] : ls[i + 1]], template[i]) for i in range(len(ls) - 1)]
-
-    return list_or_tuple(res)
-
-
-def unflat_len(obj):
-    """Return number of non-list/tuple elements in obj."""
-    if not isinstance(obj, (list, tuple)):
-        return 1
-    else:
-        return sum([unflat_len(x) for x in obj])
-
-
-def is_flat(obj):
-    """Check whether list or tuple is flat, returns true if yes, false if nested."""
-    return not any(isinstance(x, (list, tuple)) for x in obj)
-
-
 class _HeterogenousMetaEstimator(BaseMetaEstimator):
     """Handles parameter management for estimators composed of named estimators.
 

skbase/testing/utils/_conditional_fixtures.py

@@ -6,20 +6,14 @@
 from copy import deepcopy
 from typing import Callable, Dict, List
 
-import numpy as np
+from skbase._exceptions import FixtureGenerationError
+from skbase.utils._misc import _remove_single
+from skbase.validate._types import _check_list_of_str
 
 __author__: List[str] = ["fkiraly"]
 __all__: List[str] = ["create_conditional_fixtures_and_names"]
 
 
-class FixtureGenerationError(Exception):
-    """Raised when a fixture fails to generate."""
-
-    def __init__(self, fixture_name="", err=None):
-        self.fixture_name = fixture_name
-        super().__init__(f"fixture {fixture_name} failed to generate. {err}")
-
-
 def create_conditional_fixtures_and_names(
     test_name: str,
     fixture_vars: List[str],
@@ -206,41 +200,3 @@ def get_fixtures(fixture_var, **kwargs):
         fixture_prod = [deepcopy(x) for x in fixture_prod]
 
     return fixture_param_str, fixture_prod, fixture_names
-
-
-def _check_list_of_str(obj, name="obj"):
-    """Check whether obj is a list of str.
-
-    Parameters
-    ----------
-    obj : any object, check whether is list of str
-    name : str, default="obj", name of obj to display in error message
-
-    Returns
-    -------
-    obj, unaltered
-
-    Raises
-    ------
-    TypeError if obj is not list of str
-    """
-    if not isinstance(obj, list) or not np.all(isinstance(x, str) for x in obj):
-        raise TypeError(f"{name} must be a list of str")
-    return obj
-
-
-def _remove_single(x):
-    """Remove tuple wrapping from singleton.
-
-    Parameters
-    ----------
-    x : tuple
-
-    Returns
-    -------
-    x[0] if x is a singleton, otherwise x
-    """
-    if len(x) == 1:
-        return x[0]
-    else:
-        return x

skbase/validate/_types.py

@@ -10,6 +10,27 @@
 __all__: List[str] = []
 
 
+def _check_list_of_str(obj, name="obj"):
+    """Check whether obj is a list of str.
+
+    Parameters
+    ----------
+    obj : any object, check whether is list of str
+    name : str, default="obj", name of obj to display in error message
+
+    Returns
+    -------
+    obj, unaltered
+
+    Raises
+    ------
+    TypeError if obj is not list of str
+    """
+    if not isinstance(obj, list) or not all(isinstance(x, str) for x in obj):
+        raise TypeError(f"{name} must be a list of str")
+    return obj
+
+
 def _check_list_of_str_or_error(arg_to_check, arg_name):
     """Check that certain arguments are str or list of str.