# Buggy code
def _help(self, update: Update, context: CallbackContext) -> None:
    """
    Handler for /help.
    Show commands of the bot
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    forcebuy_text = (
        "*/forcebuy <pair> [<rate>]:* `Instantly buys the given pair. "
        "Optionally takes a rate at which to buy.` \n"
    )
    message = (
        "*/start:* `Starts the trader`\n"
        "*/stop:* `Stops the trader`\n"
        "*/status [table]:* `Lists all open trades`\n"
        "         *table :* `will display trades in a table`\n"
        "*/profit:* `Lists cumulative profit from all finished trades`\n"
        "*/forcesell <trade_id>|all:* `Instantly sells the given trade or all trades, "
        "regardless of profit`\n"
        f"{forcebuy_text if self._config.get('forcebuy_enable', False) else ''}"
        "*/performance:* `Show performance of each finished trade grouped by pair`\n"
        "*/daily <n>:* `Shows profit or loss per day, over the last n days`\n"
        "*/count:* `Show number of trades running compared to allowed number of trades`"
        "\n"
        "*/balance:* `Show account balance per currency`\n"
        "*/stopbuy:* `Stops buying, but handles open trades gracefully` \n"
        "*/reload_conf:* `Reload configuration file` \n"
        "*/show_config:* `Show running configuration` \n"
        "*/whitelist:* `Show current whitelist` \n"
        "*/blacklist [pair]:* `Show current blacklist, or adds one or more pairs "
        "to the blacklist.` \n"
        "*/edge:* `Shows validated pairs by Edge if it is enabeld` \n"
        "*/help:* `This help message`\n"
        "*/version:* `Show version`"
    )

    self._send_msg(message)


# Traceback (Exception)
2020-02-20 22:47:28,025 - freqtrade - ERROR - Fatal exception!
Traceback (most recent call last):
File "/opt/tradebot/freqtrade/.env/lib/python3.7/site-packages/talib/__init__.py", line 20, in wrapper
for arg in chain(args, kwargs.values())
StopIteration

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/freqtrade/freqtrade/main.py", line 36, in main
return_code = args['func'](args)
File "/freqtrade/freqtrade/commands/optimize_commands.py", line 76, in start_hyperopt
hyperopt.start()
File "/freqtrade/freqtrade/optimize/hyperopt.py", line 488, in start
preprocessed = self.backtesting.strategy.tickerdata_to_dataframe(data)
File "/freqtrade/freqtrade/strategy/interface.py", line 448, in tickerdata_to_dataframe
for pair, pair_data in tickerdata.items()}
File "/freqtrade/freqtrade/strategy/interface.py", line 448, in <dictcomp>
for pair, pair_data in tickerdata.items()}
File "/freqtrade/freqtrade/strategy/interface.py", line 464, in advise_indicators
return self.populate_indicators(dataframe, metadata)
File "/freqtrade/user_data/strategies/MyDev.py", line 205, in populate_indicators
dataframe['mfi'] = ta.MFI(dataframe)
File "talib/_abstract.pxi", line 352, in talib._ta_lib.Function.__call__
File "talib/_abstract.pxi", line 383, in talib._ta_lib.Function.__call_function
File "/opt/tradebot/freqtrade/.env/lib/python3.7/site-packages/talib/__init__.py", line 24, in wrapper
return func(*args, **kwargs)
File "talib/_func.pxi", line 8454, in talib._ta_lib.MFI
Exception: volume is not double

# Fixed code
def _help(self, update: Update, context: CallbackContext) -> None:
    """
    Handler for /help.
    Show commands of the bot
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    forcebuy_text = (
        "*/forcebuy <pair> [<rate>]:* `Instantly buys the given pair. "
        "Optionally takes a rate at which to buy.` \n"
    )
    message = (
        "*/start:* `Starts the trader`\n"
        "*/stop:* `Stops the trader`\n"
        "*/status [table]:* `Lists all open trades`\n"
        "         *table :* `will display trades in a table`\n"
        "                `pending buy orders are marked with an asterisk (*)`\n"
        "                `pending sell orders are marked with a double asterisk (**)`\n"
        "*/profit:* `Lists cumulative profit from all finished trades`\n"
        "*/forcesell <trade_id>|all:* `Instantly sells the given trade or all trades, "
        "regardless of profit`\n"
        f"{forcebuy_text if self._config.get('forcebuy_enable', False) else ''}"
        "*/performance:* `Show performance of each finished trade grouped by pair`\n"
        "*/daily <n>:* `Shows profit or loss per day, over the last n days`\n"
        "*/count:* `Show number of trades running compared to allowed number of trades`"
        "\n"
        "*/balance:* `Show account balance per currency`\n"
        "*/stopbuy:* `Stops buying, but handles open trades gracefully` \n"
        "*/reload_conf:* `Reload configuration file` \n"
        "*/show_config:* `Show running configuration` \n"
        "*/whitelist:* `Show current whitelist` \n"
        "*/blacklist [pair]:* `Show current blacklist, or adds one or more pairs "
        "to the blacklist.` \n"
        "*/edge:* `Shows validated pairs by Edge if it is enabeld` \n"
        "*/help:* `This help message`\n"
        "*/version:* `Show version`"
    )

    self._send_msg(message)