Decouple color and pixel indexing

Improve data transfer in show()

neopixel.py

@@ -234,12 +234,16 @@ class Neopixel:
         set_pixel processes the slice)
 
         :param idx: Index can either be indexing number or slice
-        :param rgb_w: Tuple of form (r, g, b) or (r, g, b, w) representing color to be used
-        :return:
+        :param rgb_w: Tuple (or list of tuples) of form (r, g, b) or (r, g, b, w) representing color to be used
+        :return: None
         """
         if type(rgb_w) is list:
-            for i in range(self.num_leds):
-                self.set_pixel(i, rgb_w[i])
+            # set some subset, if idx is a slice:
+            if type(idx) is slice:
+                for rgb_i, pixel_i in enumerate(range(*idx.indices(self.num_leds))):
+                    self.set_pixel(pixel_i, rgb_w[rgb_i])
+            else:
+                raise ValueError("Index must be a slice when setting multiple pixels as list")
         else:
             self.set_pixel(idx, rgb_w)
 
@@ -337,9 +341,9 @@ class Neopixel:
         cut = 8
         if self.W_in_mode:
             cut = 0
-        sm_put = self.sm.put
-        for pixval in self.pixels:
-            sm_put(pixval, cut)
+        
+        self.sm.put(self.pixels, cut)
+
         time.sleep(self.delay)
 
     def fill(self, rgb_w, how_bright=None):