Is there a better way to make a function silent on need?
It depends on what you are looking to do.  For localized 'quiet' code, I use this:

class NoStdStreams(object):
    def __init__(self,stdout = None, stderr = None):
        self.devnull = open(os.devnull,'w')
        self._stdout = stdout or self.devnull or sys.stdout
        self._stderr = stderr or self.devnull or sys.stderr

    def __enter__(self):
        self.old_stdout, self.old_stderr = sys.stdout, sys.stderr
        self.old_stdout.flush(); self.old_stderr.flush()
        sys.stdout, sys.stderr = self._stdout, self._stderr

    def __exit__(self, exc_type, exc_value, traceback):
        self._stdout.flush(); self._stderr.flush()
        sys.stdout = self.old_stdout
        sys.stderr = self.old_stderr
        self.devnull.close()


then it is as easy as:

with NoStdStreams():
   print('you will never see this')


You could easily adapt it to:

with NoStdStreams(verbose):
    print('you may see this')