Code

import telegramfrom telegram import ReplyKeyboardMarkupfrom telegram.ext import (    Updater,    CommandHandler,    MessageHandler,    Filters,)import requestsimport osimport sys# request token from bot in environment variablesTOKEN = os.getenv('TELEGRAM_TOKEN')mode = os.getenv('MODE')# local access (developing)if mode == 'dev':    def run(updater):        updater.start_polling()        updater.idle()# access to heroku (production)elif mode == 'prod':    def run(updater):        PORT = int(os.environ.get('PORT', '8443'))        HEROKU_APP_NAME = os.environ.get('HEROKU_APP_NAME')        updater.start_webhook(listen='0.0.0.0', port=PORT, url_path=TOKEN)        updater.bot.set_webhook(f"https://{HEROKU_APP_NAME}.herokuapp.com/{TOKEN}")else:    print('without MODE')    sys.exit()# bot start functiondef start(update, context):    keyboard = [['USD', 'AED', 'AFN', 'ALL', 'AMD'],                ['ANG', 'AOA', 'ARS', 'AUD', 'AWG'],                ['AZN', 'BAM', 'BBD', 'BDT', 'BGN'],                ['BHD', 'BIF', 'BMD', 'BND', 'BOB'],                ['BRL', 'BSD', 'BTN', 'BWP', 'BYN'],                ['BZD', 'CAD', 'CDF', 'CHF', 'CLP'],                ['CNY', 'COP', 'CRC', 'CUC', 'CUP'],                ['CVE', 'CZK', 'DJF', 'DKK', 'DOP'],                ['DZD', 'EGP', 'ERN', 'ETB', 'EUR'],                ['FJD', 'FKP', 'FOK', 'GBP', 'GEL'],                ['GGP', 'GHS', 'GIP', 'GMD', 'GNF'],                ['GTQ', 'GYD', 'HKD', 'HNL', 'HRK'],                ['HTG', 'HUF', 'IDR', 'ILS', 'IMP'],                ['INR', 'IQD', 'IRR', 'ISK', 'JMD'],                ['JOD', 'JPY', 'KES', 'KGS', 'KHR'],                ['KID', 'KMF', 'KRW', 'KWD', 'KYD'],                ['KZT', 'LAK', 'LBP', 'LKR', 'LRD'],                ['LSL', 'LYD', 'MAD', 'MDL', 'MGA'],                ['MKD', 'MMK', 'MNT', 'MOP', 'MRU'],                ['MUR', 'MVR', 'MWK', 'MXN', 'MYR'],                ['MZN', 'NAD', 'NGN', 'NIO', 'NOK'],                ['NPR', 'NZD', 'OMR', 'PAB', 'PEN'],                ['PGK', 'PHP', 'PKR', 'PLN', 'PYG'],                ['QAR', 'RON', 'RSD', 'RUB', 'RWF'],                ['SAR', 'SBD', 'SCR', 'SDG', 'SEK'],                ['SGD', 'SHP', 'SLL', 'SOS', 'SRD'],                ['SSP', 'STN', 'SYP', 'SZL', 'THB'],                ['TJS', 'TMT', 'TND', 'TOP', 'TRY'],                ['TTD', 'TVD', 'TWD', 'TZS', 'UAH'],                ['UGX', 'UYU', 'UZS', 'VES', 'VND'],                ['VUV', 'WST', 'XAF', 'XCD', 'XDR'],                ['XOF', 'XPF', 'YER', 'ZAR', 'ZMW']]    markup = ReplyKeyboardMarkup(keyboard, one_time_keyboard=True)    update.message.reply_text(        text='''        Hello! 👋🏻        What can this bot do?1️⃣-Select from the keyboard the currency you want to know the exchange value against other currencies. 2️⃣-You can also just type the currency indicator.3️⃣-Use the /exchange command followed by  the currency indicator. 4️⃣-Use /exchange_value followed by the two currencies you want to know their conversion rate.        ''',        reply_markup=markup    )# one-to-many exchange functiondef exchange(update, context):    try:        moneda = context.args[0]    except Exception as e:        print(type(e).__name__)        context.bot.send_message(            chat_id=update.effective_chat.id,            text="""                Please you don't use the command correctly,                you have to send followed by the command the                currency of which you want to know the                conversion rate.                Example:                /exchange usd                 """            )    else:        r = requests.get(f"https://v6.exchangerate-api.com/v6/YourKey/latest/{moneda}")        if r:            r_json = r.json()            text = ""            for key, value in r_json['conversion_rates'].items():                rate = f"{key} : {value}\n"                text += rate            update.message.reply_text(                text=text            )        else:            update.message.reply_text(                text="I don't recognize that currency, please send correctly the identifier of the currency in question."            )# one-to-one exchange functiondef exchange_value(update, context):    try:        currency = context.args[0].upper()        target_currency = context.args[1].upper()    except telegram.TelegramError as e:        print(e.message)        context.bot.send_message(            chat_id=update.effective_chat.id,            text="""                Please you don't use the command correctly,                you have to send followed by the command the                2 currencies of which you want to know the                conversion rate.                Example:                /exchange_value usd eur                > x USD = y EUR                """            )    else:        r = requests.get(f"https://v6.exchangerate-api.com/v6/YourKey/latest/{currency}")        if r:            r_json = r.json()            try:                rate = r_json['conversion_rates'][target_currency]            except Exception as e:                print(type(e).__name__)                update.message.reply_text(                    text="I don't recognize that currency, please send correctly the identifier of the currency in question."                )            else:                update.message.reply_text(                    text=f"1 {currency} = {rate} {target_currency}"                )        else:            update.message.reply_text(                text="I don't recognize that currency, please send correctly the identifier of the currency in question."            )# one-to-many exchange function for messagedef exchange_message(update, context):    currency = update.message.text    r = requests.get(f"https://v6.exchangerate-api.com/v6/YourKey/latest/{currency}")    if r:        r_json = r.json()        text = ""        for key, value in r_json['conversion_rates'].items():            rate = f"{key} : {value}\n"            text += rate        update.message.reply_text(            text=text        )    else:        update.message.reply_text(            text="I don't recognize that currency, please send correctly the identifier of the currency in question."        )def error_handler(update, context):    """    You can define here what to do with the errors raised by the bot.    In this case, we only print those errors to the logs.    """    try:        raise context.error    except telegram.TelegramError as e:        print(e.message)if __name__ == "__main__":    updater = Updater(token=TOKEN, use_context=True, workers=30)    # dispatcher configuration    dp = updater.dispatcher    dp.add_error_handler(error_handler)    command_handlers = {        'start': start,        'exchange': exchange,        'exchange_value': exchange_value    }    message_handlers = [        (Filters.text, exchange_message)    ]    # Init command handlers    for key, value in command_handlers.items():        dp.add_handler(CommandHandler(key, value, run_async=True))    # Init filters    for filter, callback in message_handlers:        dp.add_handler(MessageHandler(filter, callback, run_async=True))    # starting the bot    run(updater)

Examples in Telegram