RTD is a base class that should be derived from for use by functions wishing
to return real time ticking data instead of a static value.
See Real Time Data for more information.
Current value. Setting the value notifies Excel that the value has been
updated and the new value will be shown when Excel refreshes.
Called when Excel connects to this RTD instance, which occurs
shortly after an Excel function has returned an RTD object.
May be overridden in the sub-class.
Called when Excel no longer needs the RTD instance. This is
usually because there are no longer any cells that need it
or because Excel is shutting down.
XLCell represents the data and metadata for a cell in Excel passed as an xl_cell argument to a function registered with xl_func.
Some of the properties of XLCell instances can only be accessed if the calling function has been registered as a macro sheet
equivalent function .
value of the cell argument, passed in the same way as the var type.
Must be called from a macro sheet equivalent function 
string representing the address of the cell, or None if a value was passed to the function and not a cell reference.
formula of the cell as a string, or None if a value was passed to the function and not a cell reference or if the cell has no formula.
note on the cell as a string, or None if a value was passed to the function and not a cell reference or if the cell has no note.
name of the sheet this cell belongs to.
integer id of the sheet this cell belongs to.
XLRect instance with the coordinates of the cell.
True or False indicating whether the cell has been calculated or not. In almost all cases this will always
be True as Excel will automatically have recalculated the cell before passing it to the function.
from pyxll import xl_func
@xl_func("xl_cell cell: string", macro=True)
return "[value=%s, address=%s, formula=%s, note=%s]" % (
XLRect instances are accessed via XLCell.rect to get the coordinates of the cell.
First row of the range as an integer.
Last row of the range as an integer.
First column of the range as an integer.
Last column of the range as an integer.