def tax_subtract(price, tax_percentage=21):
 if (price is None):
  return None
 result = (price / ((100 + tax_percentage) / D(100)))
 return result.quantize(D('0.01'), ROUND_HALF_UP)

def tax_subtract ( price , tax_percentage = 21 ) : if ( price is None ) : return None result = ( price / ( ( 100 + tax_percentage ) / D ( 100 ) ) ) return result . quantize ( D ( '0.01' ) , ROUND_HALF_UP )
subtract the given tax_percentage from the given price .