Lots of syntax warnings with Python 3.12+

[jonhoo]

Describe the bug
With newer Python versions, the first time feedvalidator is run, it produces a large number of warnings:

/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/__init__.py:50: SyntaxWarning: invalid escape sequence '\s'
  if re.match("^\s+<\?xml",aString) and re.search("<generator.*wordpress.*</generator>",aString):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/__init__.py:75: SyntaxWarning: invalid escape sequence '\?'
  xmlver = re.match("^<\?\s*xml\s+version\s*=\s*['\"]([-a-zA-Z0-9_.:]*)['\"]",aString)
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/base.py:98: SyntaxWarning: invalid escape sequence '\w'
  return re.match(".*\w", ns).group().lower()
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:55: SyntaxWarning: invalid escape sequence '\s'
  mime_re = re.compile('[^\s()<>,;:\\"/[\]?=]+/[^\s()<>,;:\\"/[\]?=]+(\s*;\s*[^\s()<>,;:\\"/[\]?=]+=("(\\"|[^"])*"|[^\s()<>,;:\\"/[\]?=]+))*$')
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:164: SyntaxWarning: invalid escape sequence '\('
  valid_css_values = re.compile('^(#[0-9a-f]+|rgb\(\d+%?,\d*%?,?\d*%?\)?|' +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:165: SyntaxWarning: invalid escape sequence '\d'
  '\d?\.?\d?\d(cm|em|ex|in|mm|pc|pt|px|%|,|\))?)$')
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:245: SyntaxWarning: invalid escape sequence '\d'
  match = re.search(', at line (\d+), column (\d+)',str(msg))
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:268: SyntaxWarning: invalid escape sequence '\s'
  if not re.match("""^([:,;#%.\sa-zA-Z0-9!]|\w-\w|'[\s\w]+'|"[\s\w]+"|\([\d,\s]+\))*$""", style):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:270: SyntaxWarning: invalid escape sequence '\s'
  if not re.match("^(\s*[-\w]+\s*:\s*[^:;]*(;|$))*$", style):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:274: SyntaxWarning: invalid escape sequence '\w'
  for prop,value in re.findall("([-\w]+)\s*:\s*([^:;]*)",style.lower()):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:361: SyntaxWarning: invalid escape sequence '\.'
  domain_re = '''(([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([A-Z0-9\-]+\.)+))([A-Z0-9][-A-Z0-9]*)'''
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:362: SyntaxWarning: invalid escape sequence '\-'
  email_re = re.compile("([A-Z0-9_\-\+\.\']+)@" + domain_re + "$", re.I)
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:363: SyntaxWarning: invalid escape sequence '\w'
  simple_email_re = re.compile('^[\w._%+-]+@[A-Za-z][\w.-]+$')
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:429: SyntaxWarning: invalid escape sequence '\d'
  iso8601_re = re.compile("^\d\d\d\d(-\d\d(-\d\d(T\d\d:\d\d(:\d\d(\.\d*)?)?" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:430: SyntaxWarning: invalid escape sequence '\d'
  "(Z|([+-]\d\d:\d\d))?)?)?)?$")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:477: SyntaxWarning: invalid escape sequence '\d'
  iso8601_re = re.compile("^\d\d\d\d(-\d\d(-\d\d(T\d\d:\d\d(:\d\d(\.\d*)?)?" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:478: SyntaxWarning: invalid escape sequence '\d'
  "(Z|([+-]\d\d:\d\d)))?)?)?$")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:487: SyntaxWarning: invalid escape sequence '\d'
  iso8601_re = re.compile("^\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d(\.\d*)?" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:488: SyntaxWarning: invalid escape sequence '\d'
  "(Z|([+-]\d\d:\d\d))$")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:492: SyntaxWarning: invalid escape sequence '\d'
  date_re = re.compile("^\d\d\d\d-\d\d-\d\d$")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:617: SyntaxWarning: invalid escape sequence '\s'
  rfc822_re = re.compile("(((mon)|(tue)|(wed)|(thu)|(fri)|(sat)|(sun))\s*,\s*)?" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:618: SyntaxWarning: invalid escape sequence '\d'
  "\d\d?\s+((jan)|(feb)|(mar)|(apr)|(may)|(jun)|(jul)|(aug)|(sep)|(oct)|" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:619: SyntaxWarning: invalid escape sequence '\s'
  "(nov)|(dec))\s+\d\d(\d\d)?\s+\d\d:\d\d(:\d\d)?\s+(([+-]\d\d\d\d)|" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:623: SyntaxWarning: invalid escape sequence '\d'
  "\d\d? ((Jan)|(Feb)|(Mar)|(Apr)|(May)|(Jun)|(Jul)|(Aug)|(Sep)|(Oct)|" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:624: SyntaxWarning: invalid escape sequence '\d'
  "(Nov)|(Dec)) \d\d\d\d \d\d:\d\d(:\d\d)? (([+-]?\d\d[03]0)|" +
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:649: SyntaxWarning: invalid escape sequence '\('
  while value1!=value2: value1,value2=value2,re.sub('\([^(]*?\)',' ',value2)
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:660: SyntaxWarning: invalid escape sequence '\w'
  chunks=re.split('&#?(\w+);',data)
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:678: SyntaxWarning: invalid escape sequence '\s'
  anchor_re = re.compile('<a\s+href=(?:"(.*?)"|\'(.*?)\'|([\w-]+))[\s>]', re.IGNORECASE)
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:679: SyntaxWarning: invalid escape sequence '\s'
  img_re = re.compile('<img\s+[^>]*src=(?:"(.*?)"|\'(.*?)\'|([\w-]+))[\s>]', re.IGNORECASE)
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:680: SyntaxWarning: invalid escape sequence '\w'
  absref_re = re.compile("\w+:")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:720: SyntaxWarning: invalid escape sequence '\w'
  htmlEndTag_re = re.compile("</(\w+)>")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:721: SyntaxWarning: invalid escape sequence '\w'
  htmlEntity_re = re.compile("&(#?\w+)")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:829: SyntaxWarning: invalid escape sequence '\d'
  if not re.match('\d+\.?\d*$', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:834: SyntaxWarning: invalid escape sequence '\s'
  if not re.match('^\s*[A-Za-z0-9]+\s*$', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:871: SyntaxWarning: invalid escape sequence '\d'
  http_re = re.compile("(http|https)://" + addr_spec.domain_re + '(?::\d+)?' + '(/|$)', re.IGNORECASE)
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:973: SyntaxWarning: invalid escape sequence '\d'
  duration_re = re.compile("\d+(:[0-5][0-9](:[0-5][0-9])?)?$")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/validators.py:996: SyntaxWarning: invalid escape sequence '\d'
  if not re.match("^\d+(,\s*\d+)*$", self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/uri.py:83: SyntaxWarning: invalid escape sequence '\d'
  portRe = re.compile(':(\d*)$')
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/uri.py:149: SyntaxWarning: invalid escape sequence '\?'
  uriRe = re.compile('^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?$')
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/extension.py:766: SyntaxWarning: invalid escape sequence '\d'
  if not re.match('^[-+]?\d+\.?\d*[ ,][-+]?\d+\.?\d*$', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/extension.py:788: SyntaxWarning: invalid escape sequence '\d'
  if not re.match('^[-+]?\d+\.?\d*$', value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/extension.py:1160: SyntaxWarning: invalid escape sequence '\d'
  if not re.match('\d+\.?\d*\s*\w*', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/extension.py:1167: SyntaxWarning: invalid escape sequence '\d'
  if not re.match('\d+\.?\d*\s*\w*$', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/extension.py:1174: SyntaxWarning: invalid escape sequence '\d'
  if not re.match('[-+]?\d+\.?\d*\s*$', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/media.py:250: SyntaxWarning: invalid escape sequence '\d'
  npt_re = re.compile("^(now)|(\d+(\.\d+)?)|(\d+:\d\d:\d\d(\.\d+)?)$")
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/media.py:298: SyntaxWarning: invalid escape sequence '\d'
  if self.value and not re.match('\d+\.?\d*', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/media.py:307: SyntaxWarning: invalid escape sequence '\d'
  if self.value and not re.match('\d+\.?\d*', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/media.py:320: SyntaxWarning: invalid escape sequence '\d'
  if self.value and not re.match('\d+\.?\d*', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/media.py:339: SyntaxWarning: invalid escape sequence '\d'
  if self.value and not re.match('\d+\.?\d*', self.value):
/home/runner/work/pod-misc/pod-misc/feedvalidator/src/feedvalidator/image.py:73: SyntaxWarning: invalid escape sequence '\w'
  if re.match("^\w+$", ext) and ext not in ['jpg','jpeg','gif','png']:

To Reproduce

• git clone https://github.com/w3c/feedvalidator.git
• python src/demo.py "https://rustacean-station.org/podcast.rss"

Interestingly, if the command is then re-run, it produces no warnings or errors.
However, if one runs git clean -d -f -x and then re-runs, the errors are printed again.

Expected behavior
No warnings are produced

Additional context
This changed from a deprecation warning to a syntax warning in Python 3.12 (second bullet). These will become syntax errors in a future Python version. The solution here is to make these be raw strings (i.e., r"\d").

[hugovk]

Please see PR #149.