code: def rsum(self, time_period: str, num_col: str="Number", dateindex: str=None):
  		
  		try:
  			df = self._resample_("sum", time_period,
  								 num_col, dateindex)
  			self.df = df
  			if df is None:
  				self.err("Can not sum data")
  		except Exceptions as e:
  			self.err(e, "Can not sum data")
docs: Resample and add a sum the main dataframe to a time period
  
  		:param time_period: unit + period: periods are Y, M, D, H, Min, S
  		:param time_period: str
  		:param num_col: number of the new column, defaults to "Number"
  		:param num_col: str, optional
  		:param dateindex: column name to use as date index, defaults to None
  		:param dateindex: str, optional
  
  		:example: ``ds.rsum("1D")``