如何使用字符串/变量连接多个条件

Question

我有多个if条件，如果满足每个条件，则需要将其添加到字符串/变量query_str中。但是我找不到正确的语法来添加“ and”条件和等于，从而无法正确生成查询。

query_str = ""

if self.dlg.Sensor_CB.currentText() != "Select":

    query_str = query_str + and + Project_Attr_Sensor + ' == ' + self.dlg.comboBox1.currentText()

if self.dlg.Scale_CB.currentText() != "Select":

    query_str = query_str + and + Project_Attr_Scale + ' == ' + self.dlg.comboBox2.currentText()

if self.dlg.Film_CB.currentText() != "Select":

    query_str = query_str + and + Project_Attr_Film + ' == ' + self.dlg.comboBox3.currentText()

if State_Poly_Attr.capitalize() == selectedStateName.capitalize() and Project_Attr_State == selectedStateName.capitalize() + query_str:

这不起作用：

if State_Poly_Attr.capitalize() == selectedStateName.capitalize() and Project_Attr_State == selectedStateName.capitalize() + query_str: 

这正在工作

if State_Poly_Attr.capitalize() == selectedStateName.capitalize() and Project_Attr_State == selectedStateName.capitalize() and Project_Attr_Sensor == self.dlg.comboBox1.currentText() and Project_Attr_Scale == self.dlg.comboBox2.currentText() and Project_Attr_Film == self.dlg.comboBox3.currentText()

Answer 1

query_str = query_str + and + Project_Attr_Sensor + ' == ' + self.dlg.comboBox1.currentText() 

此行的语法不正确，其他语法相同，但是您能解释一下您要做什么吗？