From: Ben Darnell <ben@bendarnell.com>
Date: Sun, 14 Feb 2016 02:49:33 +0000 (-0500)
Subject: Update docs for re_unescape
X-Git-Tag: v4.4.0b1~49
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8157a19a256848ea60278afe1fff382a6525ae61;p=thirdparty%2Ftornado.git

Update docs for re_unescape
---

diff --git a/tornado/util.py b/tornado/util.py
index 71f13611b..4283d4e86 100644
--- a/tornado/util.py
+++ b/tornado/util.py
@@ -181,6 +181,7 @@ def errno_from_exception(e):
 _alphanum = frozenset(
     "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
 
+
 def _re_unescape_replacement(match):
     group = match.group(1)
     if group[0] in _alphanum:
@@ -189,10 +190,16 @@ def _re_unescape_replacement(match):
 
 _re_unescape_pattern = re.compile(r'\\(.)', re.DOTALL)
 
+
 def re_unescape(s):
-    '''
-    unescape a string escaped by ``re.escape()``
-    '''
+    """Unescape a string escaped by `re.escape`.
+
+    May raise ``ValueError`` for regular expressions which could not
+    have been produced by `re.escape` (for example, strings containing
+    ``\d`` cannot be unescaped).
+
+    .. versionadded:: 4.4
+    """
     return _re_unescape_pattern.sub(_re_unescape_replacement, s)
 
 
diff --git a/tornado/web.py b/tornado/web.py
index 1226f448c..8826c62b0 100644
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -3032,7 +3032,7 @@ class URLSpec(object):
                     unescaped_fragment = re_unescape(fragment)
                 except ValueError as exc:
                     raise ValueError(exc.args[0] + '; invalid url: %r' % pattern)
-                pieces.append(re_unescape(fragment))
+                pieces.append(unescaped_fragment)
 
         return (''.join(pieces), self.regex.groups)