Fix #128

decouple.py

@@ -5,7 +5,6 @@
 from shlex import shlex
 from io import open
 from collections import OrderedDict
-from distutils.util import strtobool
 
 # Useful for very coarse version differentiation.
 PYVERSION = sys.version_info
@@ -26,6 +25,22 @@
 
 DEFAULT_ENCODING = 'UTF-8'
 
+
+# Python 3.10 don't have strtobool anymore. So we move it here.
+TRUE_VALUES = {"y", "yes", "t", "true", "on", "1"}
+FALSE_VALUES = {"n", "no", "f", "false", "off", "0"}
+
+def strtobool(value):
+    value = value.lower()
+
+    if value in TRUE_VALUES:
+        return True
+    elif value in FALSE_VALUES:
+        return False
+
+    raise ValueError("Invalid truth value: " + value)
+
+
 class UndefinedValueError(Exception):
     pass
 
@@ -283,7 +298,6 @@ def __init__(self, flat=None, cast=text_type, choices=None):
         self._valid_values.extend(self.flat)
         self._valid_values.extend([value for value, _ in self.choices])
 
-
     def __call__(self, value):
         transform = self.cast(value)
         if transform not in self._valid_values:

tests/test_strtobool.py

@@ -0,0 +1,18 @@
+import pytest
+from decouple import strtobool
+
+
+@pytest.mark.parametrize("value", ("Y", "YES", "T", "TRUE", "ON", "1"))
+def test_true_values(value):
+    assert strtobool(value)
+
+
+@pytest.mark.parametrize("value", ("N", "NO", "F", "FALSE", "OFF", "0"))
+def test_false_values(value):
+    assert strtobool(value) is False
+
+
+def test_invalid():
+    with pytest.raises(ValueError, match="Invalid truth value"):
+        strtobool("MAYBE")
+