Fixed #25513 -- Extracted admin pagination to Paginator.get_elided_page_range().

django/core/paginator.py

@@ -25,6 +25,9 @@ class EmptyPage(InvalidPage):
 
 
 class Paginator:
+    # Translators: String used to replace omitted page numbers in elided page
+    # range generated by paginators, e.g. [1, 2, '…', 5, 6, 7, '…', 9, 10].
+    ELLIPSIS = _('…')
 
     def __init__(self, object_list, per_page, orphans=0,
                  allow_empty_first_page=True):
@@ -128,6 +131,37 @@ class Paginator:
                 stacklevel=3
             )
 
+    def get_elided_page_range(self, number=1, *, on_each_side=3, on_ends=2):
+        """
+        Return a 1-based range of pages with some values elided.
+
+        If the page range is larger than a given size, the whole range is not
+        provided and a compact form is returned instead, e.g. for a paginator
+        with 50 pages, if page 43 were the current page, the output, with the
+        default arguments, would be:
+
+            1, 2, …, 40, 41, 42, 43, 44, 45, 46, …, 49, 50.
+        """
+        number = self.validate_number(number)
+
+        if self.num_pages <= (on_each_side + on_ends) * 2:
+            yield from self.page_range
+            return
+
+        if number > (1 + on_each_side + on_ends) + 1:
+            yield from range(1, on_ends + 1)
+            yield self.ELLIPSIS
+            yield from range(number - on_each_side, number + 1)
+        else:
+            yield from range(1, number + 1)
+
+        if number < (self.num_pages - on_each_side - on_ends) - 1:
+            yield from range(number + 1, number + on_each_side + 1)
+            yield self.ELLIPSIS
+            yield from range(self.num_pages - on_ends + 1, self.num_pages + 1)
+        else:
+            yield from range(number + 1, self.num_pages + 1)
+
 
 class Page(collections.abc.Sequence):