'NoneType'對象沒有屬性'generate_ticket'

Question

我不知道爲什麼我會收到此錯誤。我對kivy相當陌生，對於那些有關kivy的更多經驗，錯誤可能是顯而易見的，所以請將您的知識傳授給我。我假設我沒有在kv語言中正確使用函數調用，或者我沒有在正確的地方定義函數。如果是這樣的話，任何人都可以提供一些指導，如何正確地做到這一點。

順便說一句，我知道一些圖書館現在還沒有python-for-android的食譜，我會在稍後談談。我也知道，我必須爲matplotlib找到解決方法/一旦我準備好移植到我的設備，就可以使用其他方法來繪製圖形。

，這裏是我的main.py代碼：

from kivy.app import App 
from kivy.uix.scatter import Scatter 
from kivy.uix.label import Label 
from kivy.uix.floatlayout import FloatLayout 
from kivy.uix.textinput import TextInput 
from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.screenmanager import ScreenManager, Screen 
from kivy.uix.gridlayout import GridLayout 
from kivy.uix.relativelayout import RelativeLayout 
from kivy.core.window import Window 
from kivy.uix.image import Image 
from kivy.graphics import BorderImage 
from kivy.graphics import Color, Rectangle, Line 


import random 
import matplotlib.pyplot as plt 
import pandas as pd 
#import pylab as pl 
import requests 
import openpyxl as xl 
#from operator import itemgetter 
from collections import Counter 
from lxml import html 
import numpy as np 

class HomeScreen(Screen): 
    pass 

class LotterySelcetionScreen(Screen): 
    pass 

class TableScreen(Screen): 
    pass 

class TutorialApp(App): 

    screen_manager = None 

    def build(self): 
     #Window.clearcolor = (1,1,1,1) 
     self.screen_manager = ScreenManager() 
     self.screen_manager.add_widget(HomeScreen(name='home')) 
     self.screen_manager.add_widget(LotterySelcetionScreen(name='lottery_selection')) 
     self.screen_manager.add_widget(TableScreen(name='table')) 

     #function to load the table form the excel file corresponding to the passed sheet name 
     def loadTable(self, sheetName): 
      lotteryData = pd.ExcelFile("Lottery databases.xlsx") #grabs and loads the file into memory 
      df = lotteryData.parse(sheetName) #loads the data table form the corresponding sheetName into the df data frame 
      return df 

     #function to display the table 
     def showTable(self, table): 
      #get the number of rows the table has 
      no_of_rows = len(table.index) 
      #display the table 

      return table.head(no_of_rows) 

     #function to display pie charts of a specific column within the database 
     #table is the database that the function will be working with 
     #and column is a numberical vaule of which column to get the data from 
     def printPieChart(self, table, column): 
      if column == 6: 
       columnList = table.iloc[:, -1:].values.T.ravel() 
      else: 
       columnList = table.iloc[:, (column - 7): (column - 6)].values.T.ravel() 
      countedList = Counter(columnList) 

      #set up the size of the pie chart 
      fig = plt.figure(figsize=[10, 10]) 
      ax = fig.add_subplot(111) 
      cmap = plt.prism() 

      #input variables for pie function 
      slices = [float(v) for v in countedList.values()] 
      colors = cmap(np.linspace(0., 1., len(slices))) 
      labels = [float(k) for k in countedList] 
      columnHeaders = list(table.columns.values) 

      #the pie chart 
      pie_wedge_collection = ax.pie(slices, colors = colors, labels = labels, labeldistance = 1.05, autopct = '%1.1f%%') 
      #get rid of the black outlines between the wedges and around the pie 
      for pie_wedge in pie_wedge_collection[0]: 
       pie_wedge.set_edgecolor('white') 
      ax.set_title(columnHeaders[column + 1]) 
      #can't display a Legends as there's too many for plt.legends() too handle 
      #return pyplot.pie([float(v) for v in countedList.values()], labels = [float(k) for k in countedList]) 

     def updateDatabase(self): 
      wb = xl.load_workbook("Lottery databases.xlsx") #load the workbook into memory 

      #list of the sheet names within the workbook 
      sheetnames = ["SuperLotto", "MegaMillions", "Powerball"] 
      days = ["Tue. ", "Wed. ", "Fri. ", "Sat. "] #days the draws on done on 
      #list of the webpages to use grab the new draws 
      webPages = ['http://www.calottery.com/play/draw-games/superlotto-plus/winning-numbers', 'http://www.calottery.com/play/draw-games/mega-millions/winning-numbers', 'http://www.calottery.com/play/draw-games/powerball/winning-numbers'] 
      x = 3 
      while x != 0: 
       ws = wb.get_sheet_by_name(sheetnames[x-1]) # which sheet to update 
       rowIndex = ws.get_highest_row() # gets the highest row index in the sheet 
       lastCellValue = ws.cell(row = rowIndex - 1, column = 0).value #gets the last value in the first column, draw number 
       page = requests.get(webPages[x-1]) #grabs the webpage needed 
       tree = html.fromstring(page.text) #puts the webpage into a tree structure to make it easy to traverse 
       #get the newest draw and date from the webpage for comparasion purposes 
       draw_and_date = tree.xpath('//*[@id="objBody_content_0_pagecontent_0_objPastWinningNumbers_rptPast_ctl01_lblDrawDateNumber"]/text()') 
       #if the table is up to date, it will move on to the next table else it will update it 
       y = int(draw_and_date[0][-4:]) - int(lastCellValue) # checks to see how many draws are missing from the table 
       if y == 0: 
        #print("The table for " + sheetnames[x-1] + " is up to date.") 
        x -= 1 #decrement x by 1 to move on to the next table 
       else: 
        #while loop to check if the table needs to be updated or not, if yes it will update it 
        while y != 0: 
         #grabs the draw and date of the missing draws from the table 
         draw_and_date = tree.xpath('//*[@id="objBody_content_0_pagecontent_0_objPastWinningNumbers_rptPast_ctl0' + str(y) + '_lblDrawDateNumber"]/text()') 
         numbers = tree.xpath(".//*[@id='content']/div[3]/table/tr[" + str(y) + "]/td[2]/span/text()") #numbers 
         numbers = [int(x) for x in numbers] # converts the text to integers 
         numbers.sort() #sort the number from smallest to largest 
         mega = tree.xpath(".//*[@id='content']/div[3]/table/tr[" + str(y) + "]/td[3]/text()") #mega number 
         mega = int(mega[0]) # converts the text to integers 
         #write to the file 
         if sheetnames[x-1] == "MegaMillions": 
          d = 0 
         else: 
          d = 1 
         if int(draw_and_date[0][-4:]) % 2 == 0: 
          # if the draw date is even then the day is a Friday/Saturday 
          ws.append([int(draw_and_date[0][-4:]), (days[d+2] + draw_and_date[0][:12]), numbers[0], numbers[1], numbers[2], numbers[3], numbers[4], mega]) # print the draw date 
         else: 
          # if the draw date is odd then the day is a Tuesday/Wednesday 
          ws.append([int(draw_and_date[0][-4:]), (days[d] + draw_and_date[0][:12]), numbers[0], numbers[1], numbers[2], numbers[3], numbers[4], mega]) 
         y -= 1 #decrement y by 1 to get the next missing draw 
        #print("Updated the " + sheetnames[x-1] + " table successfully!") 
        x -= 1 #decrement x by 1 to move on to the next table 
      wb.save("Lottery databases.xlsx") #save the workbook 
      #print("Saved the database Sucessfully!") 

     # function to get a list of the occurring numbers in each column 
     # 6 for the first number columns or 1 for the mega/powerball column 
     def getPopularList(self, table, x): 
      popular_list = list() 
      if x != 1: 
       while x != 0: 
        column_list = table.iloc[:, (0 - x): (1 - x)].values.T.ravel() # the all of the values in the column 
        counted_list = Counter(column_list) # counts how many time each value occurs within the column 
        top_five = counted_list.most_common(5) # the top five within the column 
        top_five.sort() # sorts the top five 
        popular_list = popular_list + top_five 
        x -= 1 # decrement x by 1 
      else: 
       column_list = table.iloc[:, (0 - x):].values.T.ravel() # the all of the values in the column 
       counted_list = Counter(column_list) # counts how many time each value occurs within the column 
       top_ten = counted_list.most_common(10) # the top five within the column 
       top_ten.sort() # sorts the top five 
       popular_list = popular_list + top_ten 
      #popular_list is actually a tuple of list which contains the value and how many times that value occured 
      #but we only want the values by themselves 
      popular_list_values = [y[0] for y in popular_list] #this gives us a list of the values 
      return popular_list_values 

     # Function to generate a ticket based on the popular numbers in the lottery 
     def generate_ticket(self, table): 
      firstFive = self.getPopularList(table, 6) # get the popular numbers for the first five slots 
      mega = self.getPopularList(table, 1) # gets the popular numbers for the mega/powerball slot 
      five = self.getNumbers(firstFive, 5) # gets first five numbers for the ticket 
      one = self.getNumbers(mega, 1) #gets the mega/powerball for the ticket 
      five.append(one) 
      return five 

     #function to get numbers 
     def getNumbers(self, numbers_list, x): 
      numbers = list() #empty list 
      rand_range_list = list(range(0, len(numbers_list))) #list of the numbers to choice from at random 
      if x != 1: 
       while x != 0: 
        y = random.choice(rand_range_list) #pick a number 
        #it's not making the list properly at the moment, FIX IT! 
        #numbers = numbers + numbers_list[y] #add a number to our list to return 
        numbers.append(numbers_list[y]) #append the number to the end of the list 
        rand_range_list.remove(y) #remove y from our rand_range_list to prevent any repeats 
        x -= 1 
      else: 
       numbers = random.choice(numbers_list) # add a number to our list to return 
      return numbers 

     # function to print the ticket based on which lottery it's from 
     def printTicket(self, ticket, lottery): 
      #small bubblesort for the first five numbers 
      for x in range(1, 5): 
       for y in range(0, 4): 
        if ticket[y] > ticket[y + 1]: 
         temp = ticket[y] 
         ticket[y] = ticket[y + 1] 
         ticket[y + 1] = temp 
      #print statements depending on the lottery 
      #print the ticket without any brackets 
      if lottery != "Powerball": 
       return str(ticket)[1:-4] + " Mega " + str(ticket[-1]) 
      else: 
       return str(ticket)[1:-4] + " Powerball " + str(ticket[-1]) 

     return self.screen_manager 

if __name__ == '__main__': 
    TutorialApp().run() 

我tutorial.kv：

<HomeScreen>: 
    RelativeLayout: 
     Image: 
      source: 'images/background3.jpg' 
      size_hint: None, None 
      size: self.texture_size 
      pos: self.pos 
     Button: 
      font_size: sp(30) 
      text: 'Select Lottery' 
      size_hint_x: None 
      width: self.texture_size[0] 
      size_hint_y: None 
      height: self.texture_size[1] 
      pos: root.width/2 - (self.width/2), root.height/2 
      on_press: root.manager.current = 'lottery_selection' 
     Button: 
      size_hint_x: None 
      width: self.texture_size[0] 
      size_hint_y: None 
      height: self.texture_size[1] 
      pos: root.width - self.width, 0 
      font_size: sp(30) 
      text: 'Quit' 
      on_press: app.stop() 

<LotterySelcetionScreen>: 
    BoxLayout: 
     orientation: 'vertical' 
     Button: 
      text: 'SuperLotto' 
      on_press: root.manager.current = 'table' 
     Button: 
      text: 'MegaMillions' 
     Button: 
      text: 'Powerball' 
     Button: 
      text: 'Back to home' 
      on_press: root.manager.current = 'home' 

<TableScreen>: 
    RelativeLayout: 
     Label: 
      id: label1 
      text: str(app.root.generate_ticket(app.root.loadTable('SuperLotto'))) 
      height: 150 

這裏的回溯：

Traceback (most recent call last): 
    File "/home/havik/workspace/kivyapp2.7/main.py", line 384, in <module> 
    TutorialApp().run() 
    File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 798, in run 
    root = self.build() 
    File "/home/havik/workspace/kivyapp2.7/main.py", line 207, in build 
    self.screen_manager.add_widget(TableScreen(name='table')) 
    File "/usr/lib/python2.7/dist-packages/kivy/uix/relativelayout.py", line 255, in __init__ 
    super(RelativeLayout, self).__init__(**kw) 
    File "/usr/lib/python2.7/dist-packages/kivy/uix/floatlayout.py", line 66, in __init__ 
    super(FloatLayout, self).__init__(**kwargs) 
    File "/usr/lib/python2.7/dist-packages/kivy/uix/layout.py", line 66, in __init__ 
    super(Layout, self).__init__(**kwargs) 
    File "/usr/lib/python2.7/dist-packages/kivy/uix/widget.py", line 271, in __init__ 
    Builder.apply(self) 
    File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1872, in apply 
    self._apply_rule(widget, rule, rule) 
    File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 2018, in _apply_rule 
    e), cause=tb) 
kivy.lang.BuilderException: Parser: File "/home/havik/workspace/kivyapp2.7/tutorial.kv", line 45: 
... 
     43:  Label: 
     44:   id: label1 
>> 45:   text: str(app.root.generate_ticket(app.root.loadTable('SuperLotto'))) 
     46:   height: 150 
... 
BuilderException: Parser: File "/home/havik/workspace/kivyapp2.7/tutorial.kv", line 45: 
... 
     43:  Label: 
     44:   id: label1 
>> 45:   text: str(app.root.generate_ticket(app.root.loadTable('SuperLotto'))) 
     46:   height: 150 
... 
AttributeError: 'NoneType' object has no attribute 'generate_ticket' 
    File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1649, in create_handler 
    return eval(value, idmap) 
    File "/home/havik/workspace/kivyapp2.7/tutorial.kv", line 45, in <module> 
    text: str(app.root.generate_ticket(app.root.loadTable('SuperLotto'))) 

    File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 2011, in _apply_rule 
    value, rule, rctx['ids']) 
    File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1654, in create_handler 
    cause=tb) 

Answer 1

我試過這樣做的方式提示，但我無法在構建方法中正確定義屏幕，所以我試圖擺弄kv語言的代碼，並能解決問題。我覺得很愚蠢，因爲沒有及時意識到。我只需要從str（app.root.generate_ticket（app.root.loadTable（'SuperLotto'）））中刪除root並解決了問題。

Answer 2

您在構建方法實例化一個TableScreen ，之前已設置app.root，所以app.root.generate_ticket不存在。

一種選擇是直接在構建方法中設置TableScreen內容，而不是使用kv規則。