From 2b1999476e14d534e5bb0f1be61d9a38c61bfd7a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mike=20F=C3=A4hrmann?= <mike_faehrmann@web.de>
Date: Tue, 28 May 2019 21:03:41 +0200
Subject: [PATCH] implement 'text.rextract()'

---
 gallery_dl/text.py | 10 ++++++++++
 test/test_text.py  | 26 ++++++++++++++++++++++----
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/gallery_dl/text.py b/gallery_dl/text.py
index ee987099..afe4cb18 100644
--- a/gallery_dl/text.py
+++ b/gallery_dl/text.py
@@ -124,6 +124,16 @@ def extract(txt, begin, end, pos=0):
         return None, pos
 
 
+def rextract(txt, begin, end, pos=-1):
+    try:
+        lbeg = len(begin)
+        first = txt.rindex(begin, 0, pos)
+        last = txt.index(end, first + lbeg)
+        return txt[first + lbeg:last], first
+    except (ValueError, TypeError, AttributeError):
+        return None, pos
+
+
 def extract_all(txt, rules, pos=0, values=None):
     """Calls extract for each rule and returns the result in a dict"""
     if values is None:
diff --git a/test/test_text.py b/test/test_text.py
index da7d8156..077ca6c5 100644
--- a/test/test_text.py
+++ b/test/test_text.py
@@ -161,7 +161,7 @@ class TestText(unittest.TestCase):
 
     def test_extract(self, f=text.extract):
         txt = "<a><b>"
-        self.assertEqual(f(txt, "<", ">"), ("a", 3))
+        self.assertEqual(f(txt, "<", ">"), ("a" , 3))
         self.assertEqual(f(txt, "X", ">"), (None, 0))
         self.assertEqual(f(txt, "<", "X"), (None, 0))
 
@@ -173,9 +173,27 @@ class TestText(unittest.TestCase):
 
         # invalid arguments
         for value in INVALID:
-            self.assertEqual(f(value   , "<"  , ">")  , (None, 0))
-            self.assertEqual(f(txt, value, ">")  , (None, 0))
-            self.assertEqual(f(txt, "<"  , value), (None, 0))
+            self.assertEqual(f(value, "<"  , ">")  , (None, 0))
+            self.assertEqual(f(txt  , value, ">")  , (None, 0))
+            self.assertEqual(f(txt  , "<"  , value), (None, 0))
+
+    def test_rextract(self, f=text.rextract):
+        txt = "<a><b>"
+        self.assertEqual(f(txt, "<", ">"), ("b" , 3))
+        self.assertEqual(f(txt, "X", ">"), (None, -1))
+        self.assertEqual(f(txt, "<", "X"), (None, -1))
+
+        # 'pos' argument
+        for i in range(10, 3, -1):
+            self.assertEqual(f(txt, "<", ">", i), ("b", 3))
+        for i in range(3, 0, -1):
+            self.assertEqual(f(txt, "<", ">", i), ("a", 0))
+
+        # invalid arguments
+        for value in INVALID:
+            self.assertEqual(f(value, "<"  , ">")  , (None, -1))
+            self.assertEqual(f(txt  , value, ">")  , (None, -1))
+            self.assertEqual(f(txt  , "<"  , value), (None, -1))
 
     def test_extract_all(self, f=text.extract_all):
         txt = "[c][b][a]: xyz! [d][e"