From: Martin Panter <vadmium+py@gmail.com>
Date: Sat, 15 Oct 2016 01:18:16 +0000 (+0000)
Subject: Issue #27800: Document limitation and workaround for multiple RE repetitions
X-Git-Tag: v2.7.13rc1~78
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=197332ae5a9d4885806b5cceafef650c4e8f8b77;p=python

Issue #27800: Document limitation and workaround for multiple RE repetitions
---

diff --git a/Doc/library/re.rst b/Doc/library/re.rst
index 123943474d..7b76d0c47d 100644
--- a/Doc/library/re.rst
+++ b/Doc/library/re.rst
@@ -70,6 +70,12 @@ how the regular expressions around them are interpreted. Regular
 expression pattern strings may not contain null bytes, but can specify
 the null byte using the ``\number`` notation, e.g., ``'\x00'``.
 
+Repetition qualifiers (``*``, ``+``, ``?``, ``{m,n}``, etc) cannot be
+directly nested. This avoids ambiguity with the non-greedy modifier suffix
+``?``, and with other modifiers in other implementations. To apply a second
+repetition to an inner repetition, parentheses may be used. For example,
+the expression ``(?:a{6})*`` matches any multiple of six ``'a'`` characters.
+
 
 The special characters are: