如何將變量從一個類傳遞給另一個類？

Question

我更新了這個問題。我創建了兩個窗口，並嘗試將A類中創建的變量傳遞給B類。請指出我的代碼中存在哪些問題？這裏是我的方法：

class Welcome: 

     def __init__(self, master, csv_name_sub, csv_name_ses): 
      self.entrySes = Entry(self.master, bg="LemonChiffon3") 
      self.entrySub=Entry(self.master,bg="LemonChiffon3") 
      self.csv_name_sub = str(self.entrySub.get()) 
      self.csv_name_ses = str(self.entrySes.get()) 
      #here users enter some info, they are saved to be used as file name the in following class 

class App(Welcome): 
     def __init__(self, master): 
      Welcome.__init__(self, master, csv_name_ses, csv_name_sub) #I'm trying use this line to pass the variables from the first class 
      print('session is', self.csv_name_ses) 
      print("subject is", self.csv_name_sub) 
      self.resultFile = open(
      "C:\\Users\\xxx" + self.csv_name_sub + '_' + self.csv_name_ses + 
     '_results.csv', 'w') 
     #..... 
     #other codes 

def main(): 

    root = Tk() 
    myApp = Welcome(root, csv_name_ses, csv_name_sub) 
    root.mainloop() 

if __name__ == '__main__': 
    main() 

程序可以運行，但變數csv_name_ses和csv_name_sub不傳遞給class App，因爲它們不是在課堂上打印出來。

我也嘗試過的Composition如下的方法，仍然不能解決問題：

class Welcome: 
    def __init__(self, master, csv_name_sub, csv_name_ses): 
      self.entrySes = Entry(self.master, bg="LemonChiffon3") 
      self.entrySub=Entry(self.master,bg="LemonChiffon3") 
      self.csv_name_sub = str(self.entrySub.get()) 
      self.csv_name_ses = str(self.entrySes.get()) 

class App: 
    def __init__(self, master, csv_name_ses, csv_name_sub): 
      self.csv_name_sub = csv_name_sub 
      self.csv_name_ses = csv_name_ses 
      self.welcomePage = Welcome(master, csv_name_ses, csv_name_sub) 
      print('session is', self.welcomePage.csv_name_ses) 
      print("subject is", self.welcomePage.csv_name_sub) 
    self.resultFile = open(
     "C:\\Users\\xxx + self.welcomePage.csv_name_sub + '_' + self.welcomePage.csv_name_ses + 
     '_resultsofPart.csv', 'w') 

謝謝！

Answer 1

在使用super class，從父類繼承var和值，子類需要參考的父類，這樣Welcome.csv_name_ses。

class Welcome: 

    def __init__(self, master, csv_name_sub, csv_name_ses): 
     self.entrySes = Entry(self.master, bg="LemonChiffon3") 
     self.entrySub=Entry(self.master,bg="LemonChiffon3") 
     writeToFile() 

    def writeToFile(self): 
     Welcome.csv_name_sub = str(self.entrySub.get()) 
     Welcome.csv_name_ses = str(self.entrySes.get()) 


class App(Welcome): 
    def __init__(self, master, csv_name_ses, csv_name_sub): 
     Welcome.__init__(self, master, csv_name_ses, csv_name_sub) 
     self.csv_name_sub = Welcome.csv_name_sub 
     self.csv_name_ses = Welcome.csv_name_ses #parent.var 

def main(): 

    root = Tk() 
    myApp = Welcome(root, csv_name_ses, csv_name_sub) 
    root.mainloop() 

Answer 2

問題是歡迎類需要3個參數實例化，而您只給出一個「根」。

Answer 3

由於Welcome類的構造函數爲__init__(self, master, csv_name_sub, csv_name_ses)，因此您需要提供csv_name_sub和csv_name_ses的值以及實例化此類。既然你不實際使用的csv_name_sub和csv_name_ses傳遞的值（見第4行的Welcome類的__init__功能），這可能是一個可行的解決方案：

class Welcome: 

    def __init__(self, master): 
     self.entrySes = Entry(self.master, bg="LemonChiffon3") 
     self.entrySub=Entry(self.master,bg="LemonChiffon3") 
     self.csv_name_sub = str(self.entrySub.get()) 
     self.csv_name_ses = str(self.entrySes.get()) 
     #here users enter some info, they are saved to be used as file name the in following class 

class App(Welcome): 
    def __init__(self, master): 
     Welcome.__init__(self, master) 
     print('session is', self.csv_name_ses) 
     print("subject is", self.csv_name_sub) 
     self.resultFile = open(
     "C:\\Users\\xxx" + self.csv_name_sub + '_' + self.csv_name_ses + 
    '_results.csv', 'w') 
    #..... 
    #other codes 

Answer 4

使用默認參數和or到初始化的self領域：

class Welcome: 

    def __init__(self, master, csv_name_sub=None, csv_name_ses=None): 
     self.entrySes = Entry(self.master, bg="LemonChiffon3") 
     self.entrySub=Entry(self.master,bg="LemonChiffon3") 
     self.csv_name_sub = csv_name_sub or str(self.entrySub.get()) 
     self.csv_name_ses = csv_name_ses or str(self.entrySes.get())