refactor(bits_per_word)!: validate property in Python class

BREAKING CHANGE: bits_per_word raises a ValueError instead of a
TypeError when its value is not between 8 and 32.

Author: yochem

spidev/_cspi.c

@@ -1182,33 +1182,13 @@ SpiDev_get_bits_per_word(SpiDevObject *self, void *closure)
 static int
 SpiDev_set_bits_per_word(SpiDevObject *self, PyObject *val, void *closure)
 {
-	uint8_t bits;
-
 	if (val == NULL) {
 		PyErr_SetString(PyExc_TypeError,
 			"Cannot delete attribute");
 		return -1;
 	}
-#if PY_MAJOR_VERSION < 3
-	if (PyInt_Check(val)) {
-		bits = PyInt_AS_LONG(val);
-	} else
-#endif
-	{
-		if (PyLong_Check(val)) {
-			bits = PyLong_AS_LONG(val);
-		} else {
-			PyErr_SetString(PyExc_TypeError,
-				"The bits_per_word attribute must be an integer");
-			return -1;
-		}
-	}
 
-		if (bits < 8 || bits > 32) {
-		PyErr_SetString(PyExc_TypeError,
-			"invalid bits_per_word (8 to 32)");
-		return -1;
-	}
+	uint8_t bits = PyLong_AS_LONG(val);
 
 	if (self->bits_per_word != bits) {
 		if (ioctl(self->fd, SPI_IOC_WR_BITS_PER_WORD, &bits) == -1) {

spidev/_spi.py

@@ -17,15 +17,18 @@ def __init__(
         bus: int | None,
         client: int | None,
         device: int | None = None,
-        mode: int | None = None,
         path: StrPath | None = None,
+        mode: int | None = None,
+        bits_per_word: int | None = None,
     ):
         super().__init__(bus, client)
         self.bus = bus
         self.client = client
         self.device = device
         if mode is not None:
             self.mode = mode
+        if bits_per_word is not None:
+            self.bits_per_word = bits_per_word
 
         if path and (bus or device):
             raise ValueError(
@@ -43,17 +46,34 @@ def mode(self) -> int:
         return super().mode
 
     @mode.setter
-    def mode(self, value: int) -> None:
+    def mode(self, value: int, /) -> None:
         try:
             v = int(value)
         except (TypeError, ValueError):
-            raise TypeError(f"mode must be an integer, but is {value}")
+            raise TypeError(f"mode must be an integer, but is {type(value)}")
 
         if not 0 <= v <= 3:
             raise ValueError(f"mode must be between 0 and 3, but is {v}")
 
         super().__setattr__("mode", v)
 
+    @property
+    def bits_per_word(self) -> int:
+        """Bits per word used in the xfer methods."""
+        return super().bits_per_word
+
+    @bits_per_word.setter
+    def bits_per_word(self, value: int, /) -> None:
+        try:
+            v = int(value)
+        except (TypeError, ValueError):
+            raise TypeError(f"bits_per_word must be an integer, but is {type(value)}")
+
+        if not (8 <= value <= 32):
+            raise ValueError(f"bits_per_word must be between 8 and 32, but is {v}")
+
+        super().__setattr__("bits_per_word", v)
+
     def closed(self) -> bool:
         """True if the connection is closed."""
         try: