From e15665bbda958f2ff31994b5b5108152e1935365 Mon Sep 17 00:00:00 2001
From: Hong Xu <hong@topbug.net>
Date: Sat, 27 Jul 2019 23:39:53 -0700
Subject: [PATCH] Docstring may also be prefixed with f, U, R, and F.

---
 pycodestyle.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/pycodestyle.py b/pycodestyle.py
index 4ade0871..ec65a845 100755
--- a/pycodestyle.py
+++ b/pycodestyle.py
@@ -133,7 +133,9 @@ def lru_cache(maxsize=128):  # noqa as it's a fake implementation.
 RAISE_COMMA_REGEX = re.compile(r'raise\s+\w+\s*,')
 RERAISE_COMMA_REGEX = re.compile(r'raise\s+\w+\s*,.*,\s*\w+\s*$')
 ERRORCODE_REGEX = re.compile(r'\b[A-Z]\d{3}\b')
-DOCSTRING_REGEX = re.compile(r'u?r?["\']')
+DOCSTRING_REGEX = re.compile('(u|r|ur|ru' +
+                             ('|fr|rf' if sys.version_info >= (3, 6) else '') +
+                             r')?["\']', re.IGNORECASE)
 EXTRANEOUS_WHITESPACE_REGEX = re.compile(r'[\[({] | [\]}),;:]')
 WHITESPACE_AFTER_COMMA_REGEX = re.compile(r'[,;:]\s*(?:  |\t)')
 COMPARE_SINGLETON_REGEX = re.compile(r'(\bNone|\bFalse|\bTrue)?\s*([=!]=)'