Implement distutils.strtobool in class fields.StringBoolean (#204)

* Implement distutils.strtobool in class fields.StringBoolean

To remove dependency on distutils as suggested in #203.

* Implement distutils.strtobool in class fields.StringBoolean

To remove dependency on distutils as suggested in #203.

* increase test coverage for strtobool

AUTHORS.rst

@@ -7,3 +7,4 @@ Contributors
 * Abdul muhaimin <[email protected]>
 * Marek Suppa <[email protected]>
 * Bob Callaway <[email protected]>
+* Elias Sebbar <[email protected]>

src/shillelagh/adapters/api/gsheets/fields.py

@@ -2,7 +2,6 @@
 Custom fields for the GSheets adapter.
 """
 import datetime
-from distutils.util import strtobool
 from typing import Any, List, Optional, Type
 
 from shillelagh.adapters.api.gsheets.parsing.date import (
@@ -13,7 +12,7 @@
     format_number_pattern,
     parse_number_pattern,
 )
-from shillelagh.fields import External, Field, Internal, Order
+from shillelagh.fields import External, Field, Internal, Order, StringBoolean
 from shillelagh.filters import Filter
 
 # timestamp format used in SQL queries
@@ -224,7 +223,7 @@ def parse(self, value: Optional[str]) -> Optional[bool]:
         if value is None or value == "":
             return None
 
-        return bool(strtobool(value))
+        return StringBoolean.strtobool(value)
 
     def format(self, value: Optional[bool]) -> str:
         if value is None:

src/shillelagh/fields.py

@@ -2,7 +2,6 @@
 Fields representing columns of different types and capabilities.
 """
 import datetime
-from distutils.util import strtobool
 from enum import Enum
 from typing import Any, Generic, List, Optional, Type, TypeVar, cast
 
@@ -575,7 +574,7 @@ class StringBoolean(Field[str, bool]):
     def parse(self, value: Optional[str]) -> Optional[bool]:
         if value is None:
             return None
-        return bool(strtobool(value))
+        return StringBoolean.strtobool(value)
 
     def format(self, value: Optional[bool]) -> Optional[str]:
         if value is None:
@@ -587,6 +586,22 @@ def quote(self, value: Optional[str]) -> str:
             return "NULL"
         return value
 
+    @staticmethod
+    def strtobool(val: str) -> bool:
+        """
+        Convert a string representation of truth to a boolean.
+        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.
+        """
+        val = val.lower()
+        if val in ('y', 'yes', 't', 'true', 'on', '1'):
+            return True
+        elif val in ('n', 'no', 'f', 'false', 'off', '0'):
+            return False
+        else:
+            raise ValueError("invalid truth value %s" % val)
+
 
 class IntBoolean(Field[int, bool]):
     """

tests/test_fields.py

@@ -3,6 +3,8 @@
 """
 import datetime
 
+import pytest
+
 from shillelagh.backends.apsw.db import connect
 from shillelagh.fields import (
     Blob,
@@ -263,6 +265,9 @@ def test_string_boolean() -> None:
     """
     assert StringBoolean().parse("TRUE") is True
     assert StringBoolean().parse("FALSE") is False
+    with pytest.raises(ValueError) as expected_err:
+        StringBoolean().parse("B")
+    assert str(expected_err.value) == "invalid truth value b"
     assert StringBoolean().parse(None) is None
     assert StringBoolean().format(True) == "TRUE"
     assert StringBoolean().format(False) == "FALSE"