def FormulaRule(formula=None, stopIfTrue=None, font=None, border=None, fill=None):
 rule = Rule(type='expression', formula=formula, stopIfTrue=stopIfTrue)
 rule.dxf = DifferentialStyle(font=font, border=border, fill=fill)
 return rule

def FormulaRule ( formula = None , stopIfTrue = None , font = None , border = None , fill = None ) : rule = Rule ( type = 'expression' , formula = formula , stopIfTrue = stopIfTrue ) rule . dxf = DifferentialStyle ( font = font , border = border , fill = fill ) return rule
conditional formatting with custom differential style .