arcpy中计算字段函数，给添加的字段赋值为某字符串时没成功，求教

arcpy.CalculateField_management(inFC2, fieldnamee,"!Moderate!", "PYTHON_9.3") 

codeblock="""def Glare_Rating(fieldvalue):

    if fieldvalue <0 or fieldvalue >75:

        Glare_characteristics = "Glare free zone"

    elif 0<fieldvalue and fieldvalue<14:

        Glare_characteristics = "Very strong"

    elif 14<fieldvalue and fieldvalue<30:

        Glare_characteristics = "strong"

    elif 30<fieldvalue and fieldvalue<45:

        Glare_characteristics = "Moderate"

    else:

        Glare_characteristics = "weak"

    return Glare_characteristics"""

arcpy.CalculateField_management(inFC2, "fieldname","Glare_Rating(!fieldvalue!)", "PYTHON_9.3",codeblock)