[sankaku] support alphanumeric book/pool IDs (#6757)

gallery_dl/extractor/sankaku.py

@@ -131,7 +131,7 @@ class SankakuPoolExtractor(SankakuExtractor):
     subcategory = "pool"
     directory_fmt = ("{category}", "pool", "{pool[id]} {pool[name_en]}")
     archive_fmt = "p_{pool}_{id}"
-    pattern = BASE_PATTERN + r"/(?:books|pools?/show)/(\d+)"
+    pattern = BASE_PATTERN + r"/(?:books|pools?/show)/(\w+)"
     example = "https://sankaku.app/books/12345"
 
     def __init__(self, match):

test/results/sankaku.py

@@ -105,6 +105,14 @@ __tests__ = (
     "#count"   : 5,
 },
 
+{
+    "#url"     : "https://www.sankakucomplex.com/books/8YEa7EERmD0",
+    "#comment" : "alphanumeric book/pool ID (#6757)",
+    "#category": ("booru", "sankaku", "pool"),
+    "#class"   : sankaku.SankakuPoolExtractor,
+    "#count"   : 5,
+},
+
 {
     "#url"     : "https://www.sankakucomplex.com/books/90",
     "#category": ("booru", "sankaku", "pool"),