diff --git a/ox/text.py b/ox/text.py
index d650262..dec6b3d 100644
--- a/ox/text.py
+++ b/ox/text.py
@@ -133,86 +133,86 @@ UA_NAMES = {
 }
 UA_REGEXPS = {
     'browser': [
-        '(Camino)\/(\d+)',
-        '(Chimera)\/(\d+)',
-        '(chromeframe)\/(\d+)',
-        '(Edge)\/(\d+)',
-        '(Epiphany)\/(\d+)',  # before Chrome, Chromium and Safari
-        '(Chromium)\/(\d+)',  # before Chrome
-        '(Chrome)\/(\d+)',
-        '(FBForIPhone)',
-        '(Firefox)\/(\d+)',
-        '(Galeon)\/(\d+)',
-        '(IEMobile)\/(\d+)',
-        '(iCab) (\d+)',
-        '(iCab)\/(\d+)',
-        '(konqueror)\/(\d+)',
-        '(Konqueror)\/(\d+)',
-        '(Lynx)\/(\d+)',
-        '(Netscape)\d?\/(\d+)',
-        '(NokiaBrowser)\/(\d+)',
-        '(OmniWeb)\/(\d+)',
-        '(Opera)\/.+Version\/(\d+)',
-        '(OviBrowser)\/(\d+)',
-        'Version\/(\d+).+(Safari)',
-        '(WebKit)\/(\d+)',
-        '(MSIE) (\d\d?(?!\d))',  # last, since Opera used to mask as MSIE
-        '(Trident)\/.*?rv:(\d+)',
-        '(Gecko)',
-        '(Mozilla)\/(3|4)'
+        r'(Camino)\/(\d+)',
+        r'(Chimera)\/(\d+)',
+        r'(chromeframe)\/(\d+)',
+        r'(Edge)\/(\d+)',
+        r'(Epiphany)\/(\d+)',  # before Chrome, Chromium and Safari
+        r'(Chromium)\/(\d+)',  # before Chrome
+        r'(Chrome)\/(\d+)',
+        r'(FBForIPhone)',
+        r'(Firefox)\/(\d+)',
+        r'(Galeon)\/(\d+)',
+        r'(IEMobile)\/(\d+)',
+        r'(iCab) (\d+)',
+        r'(iCab)\/(\d+)',
+        r'(konqueror)\/(\d+)',
+        r'(Konqueror)\/(\d+)',
+        r'(Lynx)\/(\d+)',
+        r'(Netscape)\d?\/(\d+)',
+        r'(NokiaBrowser)\/(\d+)',
+        r'(OmniWeb)\/(\d+)',
+        r'(Opera)\/.+Version\/(\d+)',
+        r'(OviBrowser)\/(\d+)',
+        r'Version\/(\d+).+(Safari)',
+        r'(WebKit)\/(\d+)',
+        r'(MSIE) (\d\d?(?!\d))',  # last, since Opera used to mask as MSIE
+        r'(Trident)\/.*?rv:(\d+)',
+        r'(Gecko)',
+        r'(Mozilla)\/(3|4)'
     ],
     'robot': [
-        '(BingPreview)\/(\d+)',
-        '(Google Web Preview).+Chrome\/(\d+)',
-        '(Googlebot)\/(\d+)',
-        '(WebCrawler)\/(\d+)',
-        '(Yahoo! Slurp)\/(\d+)',
-        '(YandexBot)\/([\d\.]+)',
-        '(YandexMobileBot)\/([\d\.]+)',
+        r'(BingPreview)\/(\d+)',
+        r'(Google Web Preview).+Chrome\/(\d+)',
+        r'(Googlebot)\/(\d+)',
+        r'(WebCrawler)\/(\d+)',
+        r'(Yahoo! Slurp)\/(\d+)',
+        r'(YandexBot)\/([\d\.]+)',
+        r'(YandexMobileBot)\/([\d\.]+)',
     ],
     'system': [
-        '(Android) (\d+)',
-        '(Android)',
-        '(BB)(\d+)',
-        '(BeOS)',
-        '(BlackBerry) (\d+)',
-        '(BlackBerry)',
-        '(Darwin)',
-        '(BSD) (FreeBSD|NetBSD|OpenBSD)',
-        '(CPU OS) (\d+)',
-        '(iPhone OS) (\d+)',
-        '(iPhone)',  # Opera
-        '(J2ME\/MIDP)',
-        '(Linux).+(CentOS|CrOS|Debian|Fedora|Gentoo|Mandriva|MeeGo|Mint|Red Hat|SUSE|Ubuntu|webOS)',
-        '(CentOS|CrOS|Debian|Fedora|Gentoo|Mandriva|MeeGo|Mint|Red Hat|SUSE|Ubuntu|webOS).+(Linux)',
-        '(Linux)',
-        '(Mac OS X) (10.\d+)',
-        '(Mac OS X)',
-        '(Mac_PowerPC)',
-        '(Mac_PPC)',
-        '(Macintosh)',
-        'Nintendo (Wii).+NX\/(\d+)',
-        '(PLAYSTATION) (\d+)',
-        '(PlayStation) Vita (\d+)',
-        '(RIM Tablet OS) (\d+)',
-        '(S)(60);',
-        '(Series) ?(40|60)',
-        '(Symbian OS)',
-        '(SymbianOS)\/(\d+)',
-        '(SymbOS)',
-        '(OS\/2)',
-        '(Unix) (AIX|HP-UX|IRIX|SunOS)',
-        '(Unix)',
-        '(Windows) (NT \d\.\d)',
-        '(Windows Phone) (\d+)',
-        '(Windows Phone OS) (\d+)',
-        '(Windows) (3\.1|95|98|2000|2003|CE|ME|Mobile|NT|XP)',  # Opera
-        '(Win) (9x 4\.90)',  # Firefox
-        '(Win)(16)',  # Firefox
-        '(Win)(9\d)',  # Firefox
-        '(Win)(NT)',  # Firefox
-        '(Win)(NT4\.0)',  # Firefox
-        '(X11)'
+        r'(Android) (\d+)',
+        r'(Android)',
+        r'(BB)(\d+)',
+        r'(BeOS)',
+        r'(BlackBerry) (\d+)',
+        r'(BlackBerry)',
+        r'(Darwin)',
+        r'(BSD) (FreeBSD|NetBSD|OpenBSD)',
+        r'(CPU OS) (\d+)',
+        r'(iPhone OS) (\d+)',
+        r'(iPhone)',  # Opera
+        r'(J2ME\/MIDP)',
+        r'(Linux).+(CentOS|CrOS|Debian|Fedora|Gentoo|Mandriva|MeeGo|Mint|Red Hat|SUSE|Ubuntu|webOS)',
+        r'(CentOS|CrOS|Debian|Fedora|Gentoo|Mandriva|MeeGo|Mint|Red Hat|SUSE|Ubuntu|webOS).+(Linux)',
+        r'(Linux)',
+        r'(Mac OS X) (10.\d+)',
+        r'(Mac OS X)',
+        r'(Mac_PowerPC)',
+        r'(Mac_PPC)',
+        r'(Macintosh)',
+        r'Nintendo (Wii).+NX\/(\d+)',
+        r'(PLAYSTATION) (\d+)',
+        r'(PlayStation) Vita (\d+)',
+        r'(RIM Tablet OS) (\d+)',
+        r'(S)(60);',
+        r'(Series) ?(40|60)',
+        r'(Symbian OS)',
+        r'(SymbianOS)\/(\d+)',
+        r'(SymbOS)',
+        r'(OS\/2)',
+        r'(Unix) (AIX|HP-UX|IRIX|SunOS)',
+        r'(Unix)',
+        r'(Windows) (NT \d\.\d)',
+        r'(Windows Phone) (\d+)',
+        r'(Windows Phone OS) (\d+)',
+        r'(Windows) (3\.1|95|98|2000|2003|CE|ME|Mobile|NT|XP)',  # Opera
+        r'(Win) (9x 4\.90)',  # Firefox
+        r'(Win)(16)',  # Firefox
+        r'(Win)(9\d)',  # Firefox
+        r'(Win)(NT)',  # Firefox
+        r'(Win)(NT4\.0)',  # Firefox
+        r'(X11)'
     ]
 }
 UA_VERSIONS = {
@@ -332,9 +332,9 @@ def get_sort_name(name):
 
     first_names = name.split(' ')
     last_names = []
-    if re.search('^[0-9]+$', first_names[-1]):
+    if re.search(r'^[0-9]+$', first_names[-1]):
         add_name()
-    if re.search('[(\[].+?[)\]]$', first_names[-1]):
+    if re.search(r'[(\[].+?[)\]]$', first_names[-1]):
         add_name()
     if find_name(SUFFIXES):
         add_name()
@@ -425,7 +425,7 @@ def parse_useragent(useragent):
                 matches = list(match.groups())
                 if len(matches) == 1:
                     matches.append('')
-                swap = re.match('^\d', matches[0]) or matches[1] == 'Linux'
+                swap = re.match(r'^\d', matches[0]) or matches[1] == 'Linux'
                 name = matches[1 if swap else 0]
                 version = matches[0 if swap else 1].replace('_', '.')
                 name = UA_NAMES[key][name] if name in UA_NAMES[key] else name
@@ -685,8 +685,8 @@ def sort_string(string):
     string = string.replace('Æ', 'AE').replace('Ø', 'O').replace('Þ', 'Th')
 
     # pad numbered titles
-    string = re.sub('(\d),(\d{3})', '\\1\\2', string)
-    string = re.sub('(\d+)', lambda x: '%010d' % int(x.group(0)), string)
+    string = re.sub(r'(\d),(\d{3})', '\\1\\2', string)
+    string = re.sub(r'(\d+)', lambda x: '%010d' % int(x.group(0)), string)
     return unicodedata.normalize('NFKD', string)
 
 def sorted_strings(strings, key=None):