python - Tkinter Reddit scraper(Tkinter 和 Praw)返回错误 "TypeError"

Question

我对 python 比较陌生，正在尝试创建一个 tkinter 应用程序，该应用程序从特定的 subreddit 收集信息并在 tkinter 窗口中将其返回给用户。但是，当我运行代码时，它返回错误:

类型错误:“NoneType”对象没有属性“getitem”

网络上似乎没有其他方法可以解决此问题，因此我认为在这里提问是合适的。

如果我的代码存在许多其他问题，我深表歉意，请记住，我对编码非常陌生。

谢谢，-杰夫

try:
from Tkinter import *
except ImportError:
from tkinter import *
from webbrowser import open
from datetime import date
import praw

"""
This scraper will (eventually be able to) search a user-defined subreddit and return the top ten posts from that subreddit"
"""

class redditScraper(Frame):

    def makeWidgets(self):
        intro = "Reddit Client"

        Label(self, text="What Subreddit do you wish to view?").pack()
        self.e = Entry(self)
        self.e.pack(padx=5)

        b = Button(self, text="Search Subreddit", command=self.search)
        b.pack(pady=5)


    def search(self):
        user_agent = "Reddit Client (of a sort), by (/u/CowInAFridge)"
        r = praw.Reddit(user_agent=user_agent)
        posts = r.get_subreddit(self.e.get()).get_hot(limit = 10)
        self.makeWidgets.distroy
        return posts

    def actualFrame(self):  

        self.newFrame = LabelFrame(self)
        self.newFrame.pack(fill="both", expand="yes", anchor = NW)
        posts = self.search()
        row = 0
        for p in posts:
            gotoArticle = partial(open, p.url)
            title = "(" + str(p.score) + ") " + p.title
            Label(self.newFrame, text= title, pady= 10, wraplength= 700, justify= LEFT).grid(row= row, column= 0, sticky= W)
            Button(self.newFrame, text= "Read more!", command= gotoArticle).grid(row= row+1, column= 0, sticky= W)
            row = row + 2

    def __init__(self, master):  
        Frame.__init__(self, master)        
        self.makeWidgets()
        self.actualFrame()
        self.pack()

    root = Tk()
    app = redditScraper(root)
    app.master.title("Reddit Client V.1.0")
    app.mainloop()
    root.distroy

输出的错误如下:

Traceback (most recent call last):
  File "myRedditScraper.py", line 53, in <module>
    app = redditScraper(root)
  File "myRedditScraper.py", line 49, in __init__
    self.actualFrame()
  File "myRedditScraper.py", line 37, in actualFrame
    posts = self.search()
  File "myRedditScraper.py", line 29, in search
    posts = r.get_subreddit(self.e.get()).get_hot(limit = 10)
  File "/Library/Python/2.7/site-packages/praw/__init__.py", line 1018, in get_subreddit
    return objects.Subreddit(self, subreddit_name, *args, **kwargs)
  File "/Library/Python/2.7/site-packages/praw/objects.py", line 1356, in __init__
    subreddit_name = json_dict['url'].split('/')[2]
TypeError: 'NoneType' object has no attribute '__getitem__'

Answer 1

我认为这里的问题是您在调用 app.mainloop() 之前尝试获取 Entry self.e 中的值。

在 self.actualFrame() 中，您调用 self.search()，这会进行以下调用:

posts = r.get_subreddit(self.e.get()).get_hot(limit = 10)

在尝试调用 self.e.get() 之前，您必须启动 GUI 的主循环。

我不完全清楚您的代码结构，但如果您尝试从 self.e 检索值，请等待调用 self.search() 直到调用 app.mainloop()

之后