Deprecation warning due to invalid escape sequences in Python 3.8

[tirkarthi]

Deprecation warnings are raised due to invalid escape sequences. This can be fixed by using raw strings or escaping the literals. pyupgrade also helps in automatic conversion : https://github.com/asottile/pyupgrade/

find . -iname '*.py' | grep -Ev 'test.py' | xargs -P4 -I{} python3.8 -Wall -m py_compile {}
./oembed/__init__.py:406: DeprecationWarning: invalid escape sequence \.
  self._regex = re.compile(url.replace('.', '\.')\