Fix invalid string escape sequences

Python 3.12+ emits SyntaxWarning for unrecognised backslash escapes (and
these will eventually become SyntaxErrors). Convert the affected string
literals to raw strings so the escapes are explicit:

  - scriptinterface.py: filename filter regexes (\.der, \.b64, ...).
  - obok.py: MAC-address detection regexes (\s, \-) and the title
    sanitiser ([^\s\w]).
  - flatxml2svg.py: the emitted JavaScript snippet contains \? and \d but
    also a trailing newline, so the regex part is made a raw string and
    the "\n" is concatenated separately.

All changes are value-preserving (an unrecognised escape already evaluated
to the backslash plus the character); verified the emitted JS string and
the compiled regexes are unchanged, and that both plugins now compile with
zero SyntaxWarnings.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

DeDRM_plugin/flatxml2svg.py

@@ -199,7 +199,7 @@ def convert2SVG(gdict, flat_xml, pageid, previd, nextid, svgDir, raw, meta_array
         mlst.append('<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" ><head>\n')
         mlst.append('<title>Page %d - %s by %s</title>\n' % (pageid, meta_array['Title'],meta_array['Authors']))
         mlst.append('<script><![CDATA[\n')
-        mlst.append('function gd(){var p=window.location.href.replace(/^.*\?dpi=(\d+).*$/i,"$1");return p;}\n')
+        mlst.append(r'function gd(){var p=window.location.href.replace(/^.*\?dpi=(\d+).*$/i,"$1");return p;}' + '\n')
         mlst.append('var dpi=%d;\n' % scaledpi)
         if (previd) :
             mlst.append('var prevpage="page%04d.xhtml";\n' % (previd))

DeDRM_plugin/scriptinterface.py

@@ -39,7 +39,7 @@ def decryptepub(infile, outdir, rscpath):
     if  ineptepub.adeptBook(zippath):
         # try with any keyfiles (*.der) in the rscpath
         files = os.listdir(rscpath)
-        filefilter = re.compile("\.der$", re.IGNORECASE)
+        filefilter = re.compile(r"\.der$", re.IGNORECASE)
         files = filter(filefilter.search, files)
         if files:
             for filename in files:
@@ -58,7 +58,7 @@ def decryptepub(infile, outdir, rscpath):
         # now try with ignoble epub
         # try with any keyfiles (*.b64) in the rscpath
         files = os.listdir(rscpath)
-        filefilter = re.compile("\.b64$", re.IGNORECASE)
+        filefilter = re.compile(r"\.b64$", re.IGNORECASE)
         files = filter(filefilter.search, files)
         if files:
             for filename in files:
@@ -98,7 +98,7 @@ def decryptpdf(infile, outdir, rscpath):
 
     # try with any keyfiles (*.der) in the rscpath
     files = os.listdir(rscpath)
-    filefilter = re.compile("\.der$", re.IGNORECASE)
+    filefilter = re.compile(r"\.der$", re.IGNORECASE)
     files = filter(filefilter.search, files)
     if files:
         for filename in files:
@@ -167,7 +167,7 @@ def decryptk4mobi(infile, outdir, rscpath):
             serialnums = serialstr.split(',')
     kDatabaseFiles = []
     files = os.listdir(rscpath)
-    filefilter = re.compile("\.k4i$", re.IGNORECASE)
+    filefilter = re.compile(r"\.k4i$", re.IGNORECASE)
     files = filter(filefilter.search, files)
     if files:
         for filename in files:
@@ -175,21 +175,21 @@ def decryptk4mobi(infile, outdir, rscpath):
             kDatabaseFiles.append(dpath)
     androidFiles = []
     files = os.listdir(rscpath)
-    filefilter = re.compile("\.ab$", re.IGNORECASE)
+    filefilter = re.compile(r"\.ab$", re.IGNORECASE)
     files = filter(filefilter.search, files)
     if files:
         for filename in files:
             dpath = os.path.join(rscpath,filename)
             androidFiles.append(dpath)
     files = os.listdir(rscpath)
-    filefilter = re.compile("\.db$", re.IGNORECASE)
+    filefilter = re.compile(r"\.db$", re.IGNORECASE)
     files = filter(filefilter.search, files)
     if files:
         for filename in files:
             dpath = os.path.join(rscpath,filename)
             androidFiles.append(dpath)
     files = os.listdir(rscpath)
-    filefilter = re.compile("\.xml$", re.IGNORECASE)
+    filefilter = re.compile(r"\.xml$", re.IGNORECASE)
     files = filter(filefilter.search, files)
     if files:
         for filename in files:

Obok_plugin/obok/obok.py

@@ -413,7 +413,7 @@ class KoboLibrary(object):
         """The list of all MAC addresses on this machine."""
         macaddrs = []
         if sys.platform.startswith('win'):
-            c = re.compile('\s?(' + '[0-9a-f]{2}[:\-]' * 5 + '[0-9a-f]{2})(\s|$)', re.IGNORECASE)
+            c = re.compile(r'\s?(' + r'[0-9a-f]{2}[:\-]' * 5 + r'[0-9a-f]{2})(\s|$)', re.IGNORECASE)
             try: 
                 output = subprocess.Popen('ipconfig /all', shell=True, stdout=subprocess.PIPE, text=True).stdout
                 for line in output:
@@ -427,7 +427,7 @@ class KoboLibrary(object):
                     if m:
                         macaddrs.append(re.sub("-", ":", m.group(1)).upper())
         elif sys.platform.startswith('darwin'):
-            c = re.compile('\s(' + '[0-9a-f]{2}:' * 5 + '[0-9a-f]{2})(\s|$)', re.IGNORECASE)
+            c = re.compile(r'\s(' + '[0-9a-f]{2}:' * 5 + r'[0-9a-f]{2})(\s|$)', re.IGNORECASE)
             output = subprocess.check_output('/sbin/ifconfig -a', shell=True, encoding='utf-8')
             matches = c.findall(output)
             for m in matches:
@@ -443,14 +443,14 @@ class KoboLibrary(object):
         else:
             # final fallback
             # let's try ip
-            c = re.compile('\s(' + '[0-9a-f]{2}:' * 5 + '[0-9a-f]{2})(\s|$)', re.IGNORECASE)
+            c = re.compile(r'\s(' + '[0-9a-f]{2}:' * 5 + r'[0-9a-f]{2})(\s|$)', re.IGNORECASE)
             for line in os.popen('ip -br link'):
                 m = c.search(line)
                 if m:
                     macaddrs.append(m.group(1).upper())
 
             # let's try ipconfig under wine
-            c = re.compile('\s(' + '[0-9a-f]{2}-' * 5 + '[0-9a-f]{2})(\s|$)', re.IGNORECASE)
+            c = re.compile(r'\s(' + '[0-9a-f]{2}-' * 5 + r'[0-9a-f]{2})(\s|$)', re.IGNORECASE)
             for line in os.popen('ipconfig /all'):
                 m = c.search(line)
                 if m:
@@ -649,7 +649,7 @@ def decrypt_book(book, lib):
     print("Converting {0}".format(book.title))
     zin = zipfile.ZipFile(book.filename, "r")
     # make filename out of Unicode alphanumeric and whitespace equivalents from title
-    outname = "{0}.epub".format(re.sub('[^\s\w]', '_', book.title, 0, re.UNICODE))
+    outname = "{0}.epub".format(re.sub(r'[^\s\w]', '_', book.title, 0, re.UNICODE))
     if (book.type == 'drm-free'):
         print("DRM-free book, conversion is not needed")
         shutil.copyfile(book.filename, outname)