code: def obs(self):
          
          code = "proc sql;select count(*) format best32. into :lastobs from " + self.libref + '.' + self.table + self._dsopts() + ";%put lastobs=&lastobs tom;quit;"
  
          if self.sas.nosub:
              print(code)
              return
  
          le = self._is_valid()
          if not le:
              ll = self.sas.submit(code, "text")
  
              lastobs = ll['LOG'].rpartition("lastobs=")
              lastobs = lastobs[2].partition(" tom")
              lastobs = int(lastobs[0])
          else:
              print("The SASdata object is not valid. The table doesn't exist in this SAS session at this time.")
              lastobs = None
  
          return lastobs
docs: return the number of observations for your SASdata object