Minor code simplifications.

diff --git a/bookmaker.py b/bookmaker.py
index 9da85aab88b6ef066d8cb07aa042ceaa7c19fafa..fce2175da32dafe8c0c4763b8fbc4f9f03a81ca0 100755 (executable)
--- a/bookmaker.py
+++ b/bookmaker.py
@@ -46,8 +46,6 @@ A4_HEIGHT = 29.7 * POINTS_PER_CM
 A4 = (A4_WIDTH, A4_HEIGHT)
 
 # constants specifically for --nup4
-A4_HALF_WIDTH = A4_WIDTH / 2
-A4_HALF_HEIGHT = A4_HEIGHT / 2
 CUT_DEPTH = 1.95 * POINTS_PER_CM
 CUT_WIDTH = 1.05 * POINTS_PER_CM
 MIDDLE_POINT_DEPTH = 0.4 * POINTS_PER_CM
@@ -204,7 +202,7 @@ class Nup4Geometry:
         self.shrink_for_margin = (A4_WIDTH - 2 * self.margin)/A4_WIDTH
         # NB: We define spine size un-shrunk, but .shrink_for_spine is used
         # with values shrunk for the margin, which we undo here.
-        spine_part_of_page = ((INNER_SPINE_MARGIN_PER_PAGE / A4_HALF_WIDTH)
+        spine_part_of_page = ((INNER_SPINE_MARGIN_PER_PAGE / A4_WIDTH/2)
                               / self.shrink_for_margin)
         self.shrink_for_spine = 1 - spine_part_of_page
 
@@ -452,7 +450,7 @@ def validate_ranges(
 
 
 def rotate_pages(
-        args_rotate_page: list[int],
+        args_rotate_page: Optional[list[int]],
         pages: list[Page]
         ) -> None:
     'For pages page numbered in args_rotate_page, rotate by 90°.'
@@ -631,18 +629,18 @@ def nup4_outer_page_transform(
     page.translate(ty=(1 - nup4_geometry.shrink_for_spine) * A4_HEIGHT)
     if nup4_i in {0, 1}:
         y_section = A4_HEIGHT
-        page.set_box(bottom=A4_HALF_HEIGHT, top=A4_HEIGHT)
+        page.set_box(bottom=A4_HEIGHT/2, top=A4_HEIGHT)
     else:  # nup4_in in {2, 3}
         y_section = 0
-        page.set_box(bottom=0, top=A4_HALF_HEIGHT)
+        page.set_box(bottom=0, top=A4_HEIGHT/2)
     x_section: float
     if nup4_i in {0, 2}:
         x_section = 0
-        page.set_box(left=0, right=A4_HALF_WIDTH)
+        page.set_box(left=0, right=A4_WIDTH/2)
     else:  # nup4_in in {1, 3}
         page.translate(tx=(1 - nup4_geometry.shrink_for_spine) * A4_WIDTH)
         x_section = A4_WIDTH
-        page.set_box(left=A4_HALF_WIDTH, right=A4_WIDTH)
+        page.set_box(left=A4_WIDTH/2, right=A4_WIDTH)
     page.translate(tx=x_section, ty=y_section)
     page.scale(QUARTER_SCALE_FACTOR)
 
@@ -660,10 +658,10 @@ def ornate_nup4(
         c = Canvas(packet, pagesize=A4)
         c.setLineWidth(0.1)
         c.line(0, A4_HEIGHT, A4_WIDTH, A4_HEIGHT)
-        c.line(0, A4_HALF_HEIGHT, A4_WIDTH, A4_HALF_HEIGHT)
+        c.line(0, A4_HEIGHT/2, A4_WIDTH, A4_HEIGHT/2)
         c.line(0, 0, A4_WIDTH, 0)
         c.line(0, A4_HEIGHT, 0, 0)
-        c.line(A4_HALF_WIDTH, A4_HEIGHT, A4_HALF_WIDTH, 0)
+        c.line(A4_WIDTH/2, A4_HEIGHT, A4_WIDTH/2, 0)
         c.line(A4_WIDTH, A4_HEIGHT, A4_WIDTH, 0)
         c.save()
         new_pdf = PdfReader(packet)
@@ -674,7 +672,7 @@ def ornate_nup4(
     new_page.translate(tx=printable_offset_x, ty=printable_offset_y)
     if not (args_analyze or is_front_page):
         return
-    x_left_spine_limit = A4_HALF_WIDTH * nup4_geometry.shrink_for_spine
+    x_left_spine_limit = A4_WIDTH/2 * nup4_geometry.shrink_for_spine
     x_right_spine_limit = A4_WIDTH - x_left_spine_limit
     packet = BytesIO()
     c = Canvas(packet, pagesize=A4)
@@ -701,11 +699,11 @@ def draw_cut(
     directed_half_width = 0.5 * CUT_WIDTH * direction
     outer_start_x = x_spine_limit - directed_half_width
     inner_start_x = x_spine_limit + directed_half_width
-    middle_point_y = A4_HALF_HEIGHT + MIDDLE_POINT_DEPTH * direction
-    end_point_y = A4_HALF_HEIGHT + CUT_DEPTH * direction
-    canvas.line(inner_start_x, A4_HALF_HEIGHT, x_spine_limit, end_point_y)
+    middle_point_y = A4_HEIGHT/2 + MIDDLE_POINT_DEPTH * direction
+    end_point_y = A4_HEIGHT/2 + CUT_DEPTH * direction
+    canvas.line(inner_start_x, A4_HEIGHT/2, x_spine_limit, end_point_y)
     canvas.line(x_spine_limit, end_point_y, x_spine_limit, middle_point_y)
-    canvas.line(x_spine_limit, middle_point_y, outer_start_x, A4_HALF_HEIGHT)
+    canvas.line(x_spine_limit, middle_point_y, outer_start_x, A4_HEIGHT/2)
 
 
 def main(