从另一个 class 调用 self 变量（在另一个模块中）

Question

I'm trying to call the varible "self.filename" in OpenFile() that takes the file path via QFileDialog (a GUI) in another module db.py, AddData() (as a varible "url =.."). How to call that self variable named self.filename in another module?

#main.py
class App(QMainWindow):
    def __init__(self):
        super().__init__()
        self.win = uic.loadUi(r"GUI.ui",self)
        self.initUI()
        self.win.show()

    def initUI(self):
        self.win.btOpen.clicked.connect(self.OpenFile)

    def OpenFile(self):
        self.filename=QFileDialog.getOpenFileName(self,"Open File",r"C:","csv File (*.csv)")
        db.Database()

---

#db.py
class Database():
    def __init__(self):
        super().__init__()
        self.db = sql.connect("data.db")
        self.cur=self.db.cursor()
        self.cur.execute("CREATE TABLE IF NOT EXISTS Table (Col1 real, Col2 real);")
        self.AddData()

    def AddData(self):
        """Add raw data to database"""

        url=r"table.csv" 
        with open(url) as file:
            dr = csv.DictReader(file)
            to_db = [(i['Col1'], i['Col2']) for i in dr]
        self.cur.executemany("INSERT INTO Table (Col1, Col2) VALUES (?, ?);", to_db)
        self.db.commit()

Answer 1

Why don't you simply pass the filename as a parameter to your AddData method? The result should look similar to this:

#main.py
class App(QMainWindow):
    def __init__(self):
        super().__init__()

        # initialize the database
        self.database = db.Database()
        #self.database.connect()  # optionally: connect to your database once in a method separate from the constructor

        self.win = uic.loadUi(r"GUI.ui",self)
        self.initUI()
        self.win.show()

    def initUI(self):
        self.win.btOpen.clicked.connect(self.OpenFile)

    def OpenFile(self):
        filename = QFileDialog.getOpenFileName(self,"Open File",r"C:","csv File (*.csv)")
        self.database.addData(filename)

---

#db.py
class Database():
    def __init__(self):
        super().__init__()
        self.db = sql.connect("data.db")
        self.cur = self.db.cursor()
        self.cur.execute("CREATE TABLE IF NOT EXISTS Table (Col1 real, Col2 real);")
        #self.addData()  # do not call addData here because there is no default file to load data from (at least it is not outlined in your question)

    def addData(self, filename):
        """Add raw data parsed from a csv file to this database"""

        url = filename
        with open(url) as file:
            dr = csv.DictReader(file)
            to_db = [(i['Col1'], i['Col2']) for i in dr]
        self.cur.executemany("INSERT INTO Table (Col1, Col2) VALUES (?, ?);", to_db)
        self.db.commit()

Also pay attention to consistently name your functions (camelCase). I renamed your AddData to addData .