Json Python3 tkinter标签值

我需要一些帮助，我尝试在按下按钮后更新etcprice标签值，每5秒更新一次，在terminal works中，但在tk窗口中不更新。我在这里绊倒了：（请帮帮我

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

我试图将“price”设置为“StringVar（）”，但在这种情况下，我得到了很多错误

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

非常感谢

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

解决方案是：我创建了一个名为“b”的新字符串变量，并将etcprice标签变量更改为此。

---

在我将这个b.set（price）添加到currentPrice（）def:中之后，它就开始工作了。

这个

price

变量是一个全局变量-如果您试图更改它，您需要显式地这样做：

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

def currentPrice():
    global price
    url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
    json_obj = urllib.request.urlopen(url)
    data = json.load(json_obj)
    for item, v in six.iteritems(data['result']):
        # print("ETC: $", v)
        price = str(v)
      # print(type(etcar))
        print(price)
    return price

否则，Python会将其“镜像”为函数内部的局部变量，而不会修改全局变量

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

每次单击该按钮时，继续启动越来越多的线程不是一个好主意-因此：

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

updatebtn = Button(root, text="update", command=currentPrice)

可能更有意义

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

您不需要在这里使用线程，只需“在后台”调用函数。您可以使用tkinter自己的.after函数来延迟校准函数。（顺便说一句，它使用毫秒，而不是浮点秒值）

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

可能是一种有用的功能

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

然后，在启动mainloop之前，或者当您想要启动时，请调用它一次：

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

timer(5000, root, currentPrice)

例如，如果您希望currentPrice函数在单独的线程中运行，从而在出现网络延迟时不会阻塞主GUI线程，那么您可以使用如下线程：

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()

Thread(target=currentPrice, daemon=True).start()

它将在守护进程线程中运行-如果关闭程序或ctrl-c或其他任何操作，它将自动被终止。因此，您可以将该行放入

getCurrentPriceBG

或类似函数中

    import urllib.request
    from urllib.request import *
    import json
    import six
    from tkinter import *
    import tkinter as tk
    import threading


    price = '0'

    def timer():
        threading.Timer(5.0, timer).start()
        currentPrice()

    def currentPrice():
        url = 'https://api.cryptowat.ch/markets/bitfinex/ethusd/price'
        json_obj = urllib.request.urlopen(url)
        data = json.load(json_obj)
        for item, v in six.iteritems(data['result']):
            # print("ETC: $", v)
            price = str(v)
          # print(type(etcar))
            print(price)
        return price

    def windows():
        root = Tk()
        root.geometry("500x200")

        kryptoname = Label(root, text="ETC price: ")
        kryptoname.grid(column=0, row=0)

        etcprice = Label(root, textvariable=price)
        etcprice.grid(column=1, row=0)

        updatebtn = Button(root, text="update", command=timer)
        updatebtn.grid(column=0, row=1)
        root.mainloop()

    windows()