log a one time statement

        Parameters
        ----------
        phrase : str
            statement to log

def statement(self,phrase):
        """ log a one time statement

        Parameters
        ----------
        phrase : str
            statement to log

        """
        t = datetime.now()
        s = str(t) + ' ' + str(phrase) + '\n'
        if self.echo:
            print(s,end='')
        if self.filename:
            self.f.write(s)
            self.f.flush()