Simple spreadsheet in Python (http://paddy3118.blogspot.com/2005/03/replacing-simple-spreadsheet-python.html)

spreadsheet.py

import operator, types


def value(x):
    return getattr(x, 'value', x)


class Cell(types.SimpleNamespace):
    @property
    def value(self):
        return self.op(value(self.left), value(self.right)) if self.op else self.left

    def __repr__(self):
        return str(self.value)

    namespace = locals()
    for name in "add sub mul truediv".split():
        op = getattr(operator, name)
        def operation(self, other, op=op):
            return Cell(left=self, op=op, right=other)
        def roperation(self, other, op=op):
            return Cell(right=self, op=op, left=other)
        namespace['__{}__'.format(name)] = operation
        namespace['__r{}__'.format(name)] = roperation


class Spreadsheet:
    def __setattr__(self, attr, value):
        if value == ...:
            value = getattr(self, attr)
        if not isinstance(value, Cell):
            value = Cell(left=value, op=None, right=None)
        try:
            vars(getattr(self, attr)).update(vars(value))
        except AttributeError:
            super().__setattr__(attr, value)
        print(attr, '=', value)

def webtest():
    jtag = Spreadsheet()
    jtag.lo = 640000
    jtag.hi = 640000
    jtag.period = jtag.lo + jtag.hi
    jtag.idle = 500
    jtag.lo2 = 1300
    jtag.hi2 = 100
    jtag.period2 = jtag.lo2 + jtag.hi2
    jtag.idle2 = jtag.idle * jtag.period / jtag.period2
    jtag.idle = 50
    jtag.idle2 = ...


def othertest():
    a = Spreadsheet()
    a.b = 2
    a.c = 3 + a.b
    a.b = 8
    a.c = ...
    a.d = a.b * 2 + 5
    a.c = 17
    a.d = ...
    a.b = 12
    a.d = ...


if __name__ == '__main__':
    webtest()
    print('-' * 20)
    othertest()