Deprecation warning due to invalid escape sequences in Python 3.7

[tirkarthi]

find . -iname '*.py' | grep -v example | xargs -P 4 -I{} python3.8 -Wall -m py_compile {}
./tests/testlib.py:187: DeprecationWarning: invalid escape sequence \)
  """Return a path to *pathComponents* in *appName*.
./splunklib/client.py:1875: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  if name[-1] is not ":":
./splunklib/searchcommands/internals.py:77: DeprecationWarning: invalid escape sequence \w
  """ Parses the arguments to a search command.

[amysutedja]

Rebased and merged.