Print two signatures on 4 A4 pages

1 files changed, 28 insertions, 4 deletions

diff --git a/a6_book.py b/a6_book.py
index 189018f..2a641ba 100755
--- a/a6_book.py
+++ b/a6_book.py
@@ -12,6 +12,17 @@ SIGNATURE = (
     5, 10, 7, 8,
 )
 
+SIGNATURE_32 = (
+    15, 0, 31, 16,
+    1, 14, 17, 30,
+    13, 2, 29, 18,
+    3, 12, 19, 28,
+    11, 3, 27, 20,
+    5, 10, 21, 26,
+    9, 6, 25, 22,
+    7, 8, 23, 24,
+)
+
 
 def get_parser():
     parser = argparse.ArgumentParser()
@@ -20,6 +31,12 @@ def get_parser():
         help="Name of the PDF file",
     )
     parser.add_argument(
+        "--double", "-d",
+        action="store_true",
+        help="Put two signatures on 4 A4 sheet. Pages should be a "
+        "multiple of 32",
+    )
+    parser.add_argument(
         "pagespec",
         help="Page selection. At the moment only '<start>-<end>' is supported"
     )
@@ -38,16 +55,23 @@ def main():
     except IndexError:
         parser.print_usage()
 
+    if args.double:
+        signature = SIGNATURE_32
+    else:
+        signature = SIGNATURE
+    sig_len = len(signature)
+
     pages = [str(i) for i in range(start, end+1)]
-    if len(pages) % 16 != 0:
-        empty = 16 - len(pages) % 16
+    if len(pages) % sig_len != 0:
+        empty = sig_len - len(pages) % sig_len
         pages = pages + ["{}"] * empty
 
     rearranged = []
+
     while pages:
-        for i in SIGNATURE:
+        for i in signature:
             rearranged.append(pages[i])
-        pages = pages[16:]
+        pages = pages[sig_len:]
 
     base, ext = os.path.splitext(args.file)
     out_fname = base + '-book' + ext