Add support for chapter ranges.

format_novel/format_novel.py

@@ -6,17 +6,32 @@ import sys
 import docx
 
 
-def filter_chapters(document, chapter_numbers):
-    if not chapter_numbers:
+def expand_chapter_range(chapter_request):
+    if not '-' in chapter_request:
+       return (int(chapter_request),)
+
+    chapter_range = chapter_request.split('-')
+
+    return tuple(range(int(chapter_range[0]), int(chapter_range[1]) + 1))
+
+
+def filter_chapters(document, chapter_requests):
+    if not chapter_requests:
         return
 
-    chapter_number = 0
+    chapter_numbers = {
+        chapter_number
+        for request in chapter_requests
+        for chapter_number in expand_chapter_range(request)
+    }
+
+    current_chapter_number = 0
 
     for paragraph in document.paragraphs:
         if paragraph.style.name == 'Heading 2':
-            chapter_number += 1
+            current_chapter_number += 1
 
-        if chapter_number not in chapter_numbers:
+        if current_chapter_number not in chapter_numbers:
             element = paragraph._element
             element.getparent().remove(element)
 
@@ -109,8 +124,7 @@ def parse_arguments(unparsed_arguments):
         '--chapters',
         metavar='CHAPTER',
         nargs='+',
-        type=int,
-        help='Numbers of chapters to include in output',
+        help='Chapter numbers or ranges to include in output',
     )
 
     return parser.parse_args(unparsed_arguments)