问题遇到的现象和发生背景

在学习python GUI编程
有个模块是根据所选的钢筋等级和混凝土等级这两个条件来选择最小配筋率
采用 if elif else的判断结构来进行多条件判断，但是最终输出的结果完全是随机输出的，没有按照我设置的规则进行判断

问题相关代码，请勿粘贴截图

选择容许最小配筋率

        gjdj = str (self.ui.comboBox_2.currentText())
        hntdj = str (self.ui.comboBox.currentText())
        if (hntdj == 'C30' or 'C35' or 'C40' or 'C45') and (gjdj == 'HPB300'):
            rxzxpjl = 0.20    # 容许最小配筋率
        elif (hntdj == 'C30' or 'C35' or 'C40' or 'C45') and (gjdj == 'HRB400'):
            rxzxpjl = 0.15    # 容许最小配筋率
        elif (hntdj == 'C30' or 'C35' or 'C40' or 'C45') and (gjdj == 'HRB500'):
            rxzxpjl = 0.14  # 容许最小配筋率
        elif (hntdj == 'C50') and (gjdj == 'HPB300'):
            rxzxpjl = 0.25  # 容许最小配筋率
        elif (hntdj == 'C50') and (gjdj == 'HRB400'):
            rxzxpjl = 0.20  # 容许最小配筋率
        elif (hntdj == 'C50') and (gjdj == 'HRB500'):
            rxzxpjl = 0.18  # 容许最小配筋率
        else:
            warnMessage2 = '请先输选择钢筋和混凝土等级'
            QMessageBox.warning(self.ui, "提示", warnMessage2, QMessageBox.Cancel)
        str1 = str(rxzxpjl)
        self.ui.tableWidget_2.item(0, 4).setText(str1)  # 容许最小配筋率

运行结果及报错内容

当我选择C50、HPB300时

输出的结果为0.2

当我选择C30、HRB400时

输出的结果为0.14

不止以上两组结果，其他材料等级组合输出的结果也是错的

我的解答思路和尝试过的方法

我尝试了更换and前后的顺序，并没有什么帮助

我想要达到的结果

很简单的判断语句，不知道为什么老是瞎输出。只要按照我设置的判断规则来输出结果就行

if判断的语法不对,采用or是需要在or前后加判断条件,而不都是直接加条件,下面代码可做参考

if (hntdj == 'C30' or hntdj == 'C35' or hntdj == 'C40' or hntdj == 'C45') and (gjdj == 'HPB300'):
    rxzxpjl = 0.20  # 容许最小配筋率
elif (hntdj == 'C30' or hntdj == 'C35' or hntdj == 'C40' or hntdj == 'C45') and (gjdj == 'HRB400'):
    rxzxpjl = 0.15  # 容许最小配筋率
elif (hntdj == 'C30' or hntdj == 'C35' or hntdj == 'C40' or hntdj == 'C45') and (gjdj == 'HRB500'):
    rxzxpjl = 0.14  # 容许最小配筋率
elif (hntdj == 'C50') and (gjdj == 'HPB300'):
    rxzxpjl = 0.25  # 容许最小配筋率
elif (hntdj == 'C50') and (gjdj == 'HRB400'):
    rxzxpjl = 0.20  # 容许最小配筋率
elif (hntdj == 'C50') and (gjdj == 'HRB500'):
    rxzxpjl = 0.18  # 容许最小配筋率
else:
    warnMessage2 = '请先输选择钢筋和混凝土等级'

或者使用下面的方法

if (hntdj in ['C30' ,'C35' ,'C40' ,'C45']) and (gjdj == 'HPB300'):
    rxzxpjl = 0.20  # 容许最小配筋率
elif (hntdj in ['C30' ,'C35' ,'C40' ,'C45']) and (gjdj == 'HRB400'):
    rxzxpjl = 0.15  # 容许最小配筋率
elif (hntdj in ['C30' ,'C35' ,'C40' ,'C45']) and (gjdj == 'HRB500'):
    rxzxpjl = 0.14  # 容许最小配筋率
elif (hntdj == 'C50') and (gjdj == 'HPB300'):
    rxzxpjl = 0.25  # 容许最小配筋率
elif (hntdj == 'C50') and (gjdj == 'HRB400'):
    rxzxpjl = 0.20  # 容许最小配筋率
elif (hntdj == 'C50') and (gjdj == 'HRB500'):
    rxzxpjl = 0.18  # 容许最小配筋率
else:
    warnMessage2 = '请先输选择钢筋和混凝土等级'

         if (hntdj == 'C30' or 'C35' or 'C40' or 'C45') and (gjdj == 'HPB300'):     #前半段是错的, or不是你想的意思，应该改成下面这样
         if (hntdj == 'C30' or hntdj == 'C35' or hntdj == 'C40' or hntdj == 'C45') and (gjdj == 'HPB300') 
         #或者直接改成下面这样更简单
         if hntdj in ['C30','C35','C40','C45'] and gjdj=='HPB300'