[MNT] python 3.12 compatibility - replace distutils calls with equivalent functionality

sktime/datasets/_readers_writers/tsf.py

@@ -5,12 +5,12 @@
 __all__ = ["load_tsf_to_dataframe"]
 
 from datetime import datetime
-from distutils.util import strtobool
 from typing import Dict
 
 import pandas as pd
 
 from sktime.datatypes import MTYPE_LIST_HIERARCHICAL, convert
+from sktime.utils.strtobool import strtobool
 
 
 def _convert_tsf_to_hierarchical(

sktime/transformations/series/fourier.py

@@ -4,7 +4,6 @@
 __author__ = ["ltsaprounis", "blazingbhavneek"]
 
 import warnings
-from distutils.log import warn
 from typing import List, Optional
 
 import numpy as np
@@ -181,9 +180,10 @@ def _fit(self, X, y=None):
             if self.freq_ is None:
                 ValueError("X has no known frequency and none is supplied")
             if self.freq_ == time_index.freq and self.freq_ != self.freq:
-                warn(
-                    f"Using frequency from index: {time_index.freq}, which \
-                     does not match the frequency given:{self.freq}."
+                warnings.warn(
+                    f"Using frequency from index: {time_index.freq}, which"
+                    f"does not match the frequency given:{self.freq}.",
+                    stacklevel=2,
                 )
             time_index = time_index.to_period(self.freq_)
         # this is used to make sure that time t is calculated with reference to

sktime/utils/strtobool.py

@@ -0,0 +1,35 @@
+"""String-to-int coercion utility strtobool formerly in deprecated distutils."""
+
+
+# distutils has been removed in Python 3.12,
+# but this function is still used in parts of the sktime codebase
+def strtobool(val):
+    """Convert a string representation of truth to int, true (1) or false (0).
+
+    True values are 'y', 'yes', 't', 'true', 'on', and '1'; false values
+    are 'n', 'no', 'f', 'false', 'off', and '0'.  Raises ValueError if
+    'val' is anything else.
+
+    Parameters
+    ----------
+    val : str
+        A string representation of truth.
+
+    Returns
+    -------
+    int, 0 or 1
+        val coerced to int
+        1 if val is a true value, 0 if val is a false value (see above)
+
+    Raises
+    ------
+    ValueError
+        If val is anything other than the strings above.
+    """
+    val = val.lower()
+    if val in ("y", "yes", "t", "true", "on", "1"):
+        return 1
+    elif val in ("n", "no", "f", "false", "off", "0"):
+        return 0
+    else:
+        raise ValueError(f"invalid truth value {val!r}")