code: def set(self, name, value, ex=None, px=None, nx=False, xx=False):
          
          pieces = [name, value]
          if ex:
              pieces.append('EX')
              if isinstance(ex, datetime.timedelta):
                  ex = ex.seconds + ex.days * 24 * 3600
              pieces.append(ex)
          if px:
              pieces.append('PX')
              if isinstance(px, datetime.timedelta):
                  ms = int(px.microseconds / 1000)
                  px = (px.seconds + px.days * 24 * 3600) * 1000 + ms
              pieces.append(px)
  
          if nx:
              pieces.append('NX')
          if xx:
              pieces.append('XX')
          return self.execute('set', *pieces)
docs: Set the value at key ``name`` to ``value``
  
          :param ex: sets an expire flag on key ``name`` for ``ex`` seconds.
          :param px: sets an expire flag on key ``name`` for ``px`` milliseconds.
          :param nx: if set to True, set the value at key ``name`` to ``value``
              if it does not already exist.
          :param xx: if set to True, set the value at key ``name`` to ``value``
              if it already exists.