parameters: (table,record_id=None)
return_statement: return crud.read(db[table],record_id)
docstring: ## read and display a record
          - ``table`` is the name of a table
          - ``record_id`` is a record number
docstring_summary: ## read and display a record
          - ``table`` is the name of a table
          - ``record_id`` is a record number
docstring_tokens: ## read and display a record - table is the name of a table - record_id is a record number
function: def read(table,record_id=None):
          """
          ## read and display a record
          - ``table`` is the name of a table
          - ``record_id`` is a record number
          """
          if not record_id: record_id=request.args(-1)
          if not record_id.isdigit(): return XML('no data')
          return crud.read(db[table],record_id)
function_tokens: def read ( table , record_id = None ) : if not record_id : record_id = request . args ( - 1 ) if not record_id . isdigit ( ) : return XML ( 'no data' ) return crud . read ( db [ table ] , record_id )