Update _pages.py - fix sorting for > 10 pages

CHANGELOG.md

@@ -2,6 +2,12 @@
 All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
+## [UNRELEASED]
+
+## Fixed
+
+- [#2565](https://github.com/plotly/dash/pull/2565) Fix sorting for > 10 pages, fix [#2564](https://github.com/plotly/dash/issues/2564)
+
 ## [2.10.2] - 2023-05-31
 
 ## Changed

dash/_pages.py

@@ -355,10 +355,16 @@ def register_page(
         )
         p["relative_path"] = get_relative_path(p["path"])
 
-    # Sort by order and module, then by module
+    # Sort numeric orders first, then string orders, then no order,
+    # finally by module name for matching orders
     for page in sorted(
         PAGE_REGISTRY.values(),
-        key=lambda i: (str(i.get("order", i["module"])), i["module"]),
+        key=lambda i: (
+            i["order"] is None,  # False (order given) sorts before True
+            i["order"] if isinstance(i["order"], (int, float)) else float("inf"),
+            str(i["order"]),
+            i["module"],
+        ),
     ):
         PAGE_REGISTRY.move_to_end(page["module"])
 

tests/integration/multi_page/test_pages_order.py

@@ -3,7 +3,6 @@
 
 
 def test_paor001_order(dash_duo, clear_pages_state):
-
     app = Dash(__name__, use_pages=True, suppress_callback_exceptions=True)
 
     dash.register_page(
@@ -24,6 +23,53 @@ def test_paor001_order(dash_duo, clear_pages_state):
         order=0,
         id="multi_layout3",
     )
+    # Test more than 10 pages to ensure the supplied order is sorted correctly
+    for order_int in range(3, 13):
+        dash.register_page(
+            f"multi_layout{order_int + 1}",
+            layout=html.Div(
+                f"text for multi_layout{order_int + 1}",
+                id=f"text_multi_layout{order_int + 1}",
+            ),
+            order=order_int,
+            id=f"multi_layout{order_int + 1}",
+        )
+    # Test fractional ordering
+    dash.register_page(
+        "multi_layout3.5",
+        layout=html.Div("text for multi_layout3.5", id="text_multi_layout3.5"),
+        order=3.5,
+        id="multi_layout3.5",
+    )
+    # Test no order given
+    dash.register_page(
+        "multi_layout14",
+        layout=html.Div("text for multi_layout14", id="text_multi_layout14"),
+        id="multi_layout14",
+    )
+    dash.register_page(
+        "multi_layout15",
+        layout=html.Div("text for multi_layout15", id="text_multi_layout15"),
+        id="multi_layout15",
+    )
+    # Test string for order
+    dash.register_page(
+        "first_string_order",
+        layout=html.Div("text for string_order", id="text_string_order"),
+        order="2a",
+        id="first_string_order",
+    )
+    dash.register_page(
+        "aaa_first_with_no_order",
+        layout=html.Div("text for aaa", id="text_aaa"),
+        id="aaa_first_with_no_order",
+    )
+    dash.register_page(
+        "yyy_last_string_order",
+        layout=html.Div("text for yyy", id="text_yyy"),
+        order="zzz",
+        id="yyy_last_string_order",
+    )
 
     app.layout = html.Div(
         [
@@ -48,6 +94,22 @@ def test_paor001_order(dash_duo, clear_pages_state):
         "multi_layout3",
         "multi_layout2",
         "multi_layout1",
+        "multi_layout4",
+        "multi_layout3.5",
+        "multi_layout5",
+        "multi_layout6",
+        "multi_layout7",
+        "multi_layout8",
+        "multi_layout9",
+        "multi_layout10",
+        "multi_layout11",
+        "multi_layout12",
+        "multi_layout13",
+        "first_string_order",
+        "yyy_last_string_order",
+        "aaa_first_with_no_order",
+        "multi_layout14",
+        "multi_layout15",
         "pages.defaults",
         "pages.metas",
         "pages.not_found_404",