python中的KeyError报错

from util import str_util
#业务逻辑：兼容不同的结构体：resCode转化数据
#检查字典中是否存在键 if 'resCode' not in resultJson
    if 'resCode' not in resultJson:
        if 'returnCode' in resultJson:
            resCode = resultJson["returnCode"]
            if str_util.is_not_blank(resCode) and resCode == "1":
                resCode = "000000"
        
        if 'status' in resultJson:
            resCode = resultJson["status"]
            if resCode == 20000:
                resCode = "000000"
    else:
        resCode = resultJson["resCode"]
        

str_util.py
def is_blank(str: str):
    if str and str.strip():
        return False
    return True


def is_not_blank(str: str):
    return is_blank(str) == False