Factory function for producing ConfigurableAction classes which are
realizations of arithmetic operations.
Parameters
----------
className : `str`
The name of the class that will be produced
expr : `str`
An arithmetic expression that will be parsed to produce the output
ConfigurableAction. Individual variable names will be the name of
individual `ConfigActions` inside the expression (i.e. "x+y" will
produce an action with configAction.actions.x and
configAction.actions.y). Expression can contain arithmatic python
operators as well as; sin, cos, sinh, cosh, log (which is base 10).
exprDefaults : `Mapping` of `str` to `DataFrameAction` optional
A mapping of strings which correspond to the names in the expression to
values which are default `ConfigurableActions` to assign in the
expression. If no default for a action is supplied `SingleColumnAction`
is set as the default.
docstring : `str`
A string that is assigned as the resulting classes docstring
Returns
-------
action : `Type` of `DataFrameAction`
A `DataFrameAction` class that was programatically constructed from the
input expression.
Definition at line 83 of file _evalColumnExpression.py.