python validator with regex and value range

i want to define a input validator function. Which one is the combination of a regex and a value range. can you help me please?

def validator(feld, e_min, e_max, e_komma=2):
    s_reg_ex = "([+-]|)[0-9]+\.[0-9]{" + str(e_komma) + "}"
    reg_ex = QRegExp(s_reg_ex)
    input_validator = QRegExpValidator(reg_ex, feld)
    input_validator_2 = QIntValidator(e_min, e_max)
    feld.setValidator(input_validator & input_validator_2)