class_docstr: Expression base class
  
  Expression is designed to handle the calculation of data with the format below
  data with two dimension for each instrument,
  
  - feature
  - time:  it  could be observation time or period time.
  
      - period time is designed for Point-in-time database.  For example, the period time maybe 2014Q4, its value can observed for multiple times(different value may be observed at different time due to amendment).
class_docstr_tok: ["Expression","base","class","Expression","is","designed","to","handle","the","calculation","of","data","with","the","format","below","data","with","two","dimension","for","each","instrument",",","-","feature","-","time",":","it","could","be","observation","time","or","period","time",".","-","period","time","is","designed","for","Point-in-time","database",".","For","example",",","the","period","time","maybe","2014Q4",",","its","value","can","observed","for","multiple","times","(","different","value","may","be","observed","at","different","time","due","to","amendment",")","."]
code: def __rtruediv__(self, other):
      from .ops import Div  # pylint: disable=C0415
  
      return Div(other, self)
  
imports: from __future__ import division
  from __future__ import print_function
  import abc
  import pandas
  from ..log import get_module_logger
label_desc: Use image node_id 18 for calling the Expression obj's underlying member method code with example usage: obj.__rtruediv__(other) and returns: Div