Tkinter回调中出现异常:json。解码器。JSONDecodeError:应为值:第1行第1列(字符0)

我收到错误: json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0) ,在我的小Python程序(Jupyter笔记本上)中,阻止我实际计算货币。

它应该是一个简单的货币转换器应用程序;然而,当我在“convert”函数内使用计算代码时,就会出现上述错误,否则在函数外,代码会使用API键很好地检索数据,并转换货币。

感谢大家对我的帮助,也因为我是新来的,所以对我的代码有任何其他建议(这可能在 肾盂道 )将不胜感激。

错误:

> Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\ProgramData\Anaconda3\lib\tkinter\__init__.py", line 1699, in __call__
    return self.func(*args)
  File "<ipython-input-41-161d07d3ddae>", line 29, in convert
    currency_Collection = json.loads(str(r.text))
  File "C:\ProgramData\Anaconda3\lib\json\__init__.py", line 354, in loads
    return _default_decoder.decode(s)
  File "C:\ProgramData\Anaconda3\lib\json\decoder.py", line 339, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "C:\ProgramData\Anaconda3\lib\json\decoder.py", line 357, in raw_decode
    raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

代码:

#-------------Imports
import requests
import json

from tkinter import *
from tkinter import ttk

#-------------Variables
value_ToConvert = float()
value_Converted = float()

currencyBase_ToConvert  = ''
currencyBase_Converted = ''

countries = ['ALL: Albania [Lek]','AMD: Armenia [Armenian Dram]','ANG: Curaço [Netherlands Antillean Guilder]','AOA: Angola [Kwanza]','ARS: Argentina [Argentine Peso]','AUD: Australia [Australian Dollar]','AZN: Azerbaijan [Azerbaijanian Manat]','BBD: Barbados [Barbados Dollar]','BDT: Bangladesh [Taka]','BGN: Bulgaria [Bulgarian Lev]','BHD: Bahrain [Bahraini Dinar]','BRL: Brazil [Brazilian Real]','BSD: Bahamas [Bahamian Dollar]','BWP: Botswana [Pula]','BYN: Belarus [Belarusian Ruble]','CAD: Canada [Canadian Dollar]','CDF: Congo [Franc Congolais]','CLP: Chile [Chilean Peso]','CNY: China [Yuan Renminbi]','COP: Colombia [Colombian Peso]','CZK: Czech Republic [Czech Koruna]','DKK: Denmark [Danish Krone]','DOP: Dominican Republic [Dominican Peso]','EGP: Egypt [Egyptian Pound]','ETB: Ethiopia [Ethiopian Birr]','EUR: Åland Islands [Euro]','FJD: Fiji [Fiji Dollar]','GBP: Guernsey [Pound Sterling]','GEL: Georgia [Lari]','GHS: Ghana [Ghana Cedi]','GTQ: Guatemala [Quetzal]','HKD: Hong Kong [Hong Kong Dollar]','HNL: Honduras [Lempira]','HRK: Croatia [Croatian Kuna]','HUF: Hungary [Forint]','IDR: Indonesia [Rupiah]','ILS: Israel [New Israeli Sheqel]','INR: India [Indian Rupee]','IQD: Iraq [Iraqi Dinar]','IRR: Iran, Islamic Republic Of [Iranian Rial]','ISK: Iceland [Iceland Krona]','JMD: Jamaica [Jamaican Dollar]','JOD: Jordan [Jordanian Dinar]','JPY: Japan [Yen]','KES: Kenya [Kenyan Shilling]','KHR: Cambodia [Riel]','KRW: Korea, Republic of [Won]','KWD: Kuwait [Kuwaiti Dinar]','KZT: Kazakhstan [Tenge]','LAK: Lao Peoples Democratic Republic [Kip]','LBP: Lebanon [Lebanese Pound]','LKR: Sri Lanka [Sri Lanka Rupee]','MAD: Morocco [Moroccan Dirham]','MDL: Moldova, Republic of [Moldovan Leu]','MKD: Macedonia [Denar]','MMK: Myanmar [Kyat]','MUR: Mauritius [Mauritius Rupee]','MXN: Mexico [Mexican Peso]','MYR: Malaysia [Malaysian Ringgit]','NAD: Namibia [Namibia Dollar]','NGN: Nigeria [Naira]','NOK: Norway [Norwegian Krone]','NZD: New Zealand [New Zealand Dollar]','OMR: Oman [Rial Omani]','PAB: Panama [Balboa]','PEN: Peru [Nuevo Sol]','PGK: Papua New Guinea [Kina]','PHP: Philippines [Philippine Peso]','PKR: Pakistan [Pakistan Rupee]','PLN: Poland [Zloty]','PYG: Paraguay [Guarani]','QAR: Qatar [Qatari Rial]','RON: Romania [New Romanian Leu]','RSD: Serbia [Serbian Dinar]','RUB: Russian Federation [Russian Ruble]','SAR: Saudi Arabia [Saudi Riyal]','SCR: Seychelles [Seychelles Rupee]','SEK: Sweden [Swedish Krona]','SGD: Singapore [Singapore Dollar]','THB: Thailand [Baht]','TJS: Tajikistan [Somoni]','TND: Tunisia [Tunisian Dinar]','TRY: Turkey [New Turkish Lira]','TTD: Trinidad and Tobago [Trinidad and Tobago Dollar]','TWD: Taiwan, Province of China [New Taiwan Dollar]','TZS: Tanzania [Tanzanian Shilling]','UAH: Ukraine [Hryvnia]','USD: United States [US Dollar]','UYU: Uruguay [Peso Uruguayo]','UZS: Uzbekistan [Uzbekistan Sum]','VEF: Venezuela [Bolivar]','VND: Viet Nam [Dong]','XAF: Cameroon [CFA Franc BEAC ‡]','XCD: Anguilla [East Caribbean Dollar]','XOF: Benin [CFA Franc BCEAO †]','XPF: French Polynesia [CFP Franc]','ZAR: South Africa [Rand]','ZMW: Zambia [Kwacha]']

#-------------Definitions

try:
    def convert():
        value_ToConvert = value_entry.get()
        currencyBase_ToConvert = currencyBase_ToConvert_Box.get()
        currencyBase_Converted = currencyBase_Converted_Box.get()

        currencyBase_Parameter = '/' + currencyBase_ToConvert
        r = requests.get('https://v3.exchangerate-api.com/bulk/b76715d91ecbbc9c14a229e8' + currencyBase_Parameter)

        currency_Collection = dict()
        currency_Collection = json.loads(r.text)
        currency_Rates = dict(currency_Collection['rates'])
        value_Converted = float(value_ToConvert) * float(currency_Rates[currencyBase_Converted])
        print (value_Converted)
        currencyBase_Converted_Label = ttk.Label(mainframe, text = value_Converted).grid(column = 3, row = 2, stick = W, padx = 10, pady = 20)
except Exception:
    print(Exception)

def reset():
    value_ToConvert = 0.0
    value_Converted = 0.0

    currencyBase_ToConvert = ''
    currencyBase_Converted = ''

    currencyBase_ToConvert_Box.set("")
    currencyBase_Converted_Box.set("")
    return

def exit():
    root.destroy()
    return

#-------------Creating Frame
root = Tk()
root.title("Currency Converter")

mainframe = ttk.Frame(root, padding = "3 3 12 12")
root.geometry ('350x200+0+0')
mainframe.grid(column = 0, row = 0, sticky = (N, W, E, S))
mainframe.columnconfigure(0, weight = 1)
mainframe.rowconfigure(0, weight = 1)

#Row: 1
ttk.Label(mainframe, text = "HAVE").grid(column = 1, row = 1, sticky = (N,W), padx = 10, pady = 20)

currencyBase_ToConvert_Box = ttk.Combobox(mainframe, textvariable = currencyBase_ToConvert, state = 'readonly')
currencyBase_ToConvert_Box['values'] = countries
currencyBase_ToConvert_Box.current(0)
currencyBase_ToConvert_Box.grid(column = 2, row = 1, padx = 0, pady = 20)
currencyBase_ToConvert_Box.set("")

value_entry = ttk.Entry(mainframe, width = 10, textvariable = value_ToConvert)
value_entry.grid(column = 3, row = 1, sticky = (N,E), padx = 10, pady = 20)

#Row: 2
ttk.Label(mainframe, text = "WANT").grid(column = 1, row = 2, stick = W, padx = 10, pady = 20)

currencyBase_Converted_Box = ttk.Combobox(mainframe, textvariable = currencyBase_Converted, state = 'readonly')
currencyBase_Converted_Box['values'] = countries
currencyBase_Converted_Box.current(0)
currencyBase_Converted_Box.grid(column = 2, row = 2, padx = 0, pady = 20)
currencyBase_Converted_Box.set("")

#Row: 3
btnConvert = Button(mainframe, text = "Convert", padx = 40, pady = 20, width = 1, height = 1, command = convert).grid(column = 1, row = 3)
btnReset = Button(mainframe, text = "Reset", padx = 40, pady = 20, width = 1, height = 1, command = reset).grid(column = 2, row = 3)
btnExit = Button(mainframe, text = "Exit", padx = 40, pady = 20, width = 1, height = 1, command = exit).grid(column = 3, row = 3)

root.mainloop()

我添加了一张图片来帮助说明我试图实现的目标,输出(在“转换”按钮被激活后创建)应该位于右上角标签的下方,在:第3列;第2行。 enter image description here