# Buggy code
def print_epoch_details(
    results,
    total_epochs,
    print_json: bool,
    no_header: bool = False,
    header_str: str = None,
) -> None:
    """
    Display details of the hyperopt result
    """
    params = results.get("params_details", {})

    # Default header string
    if header_str is None:
        header_str = "Best result"

    if not no_header:
        explanation_str = Hyperopt._format_explanation_string(results, total_epochs)
        print(f"\n{header_str}:\n\n{explanation_str}\n")

    if print_json:
        result_dict: Dict = {}
        for s in ["buy", "sell", "roi", "stoploss", "trailing"]:
            Hyperopt._params_update_for_json(result_dict, params, s)
        print(
            rapidjson.dumps(result_dict, default=str, number_mode=rapidjson.NM_NATIVE)
        )

    else:
        Hyperopt._params_pretty_print(params, "buy", "Buy hyperspace params:")
        Hyperopt._params_pretty_print(params, "sell", "Sell hyperspace params:")
        Hyperopt._params_pretty_print(params, "roi", "ROI table:")
        Hyperopt._params_pretty_print(params, "stoploss", "Stoploss:")
        Hyperopt._params_pretty_print(params, "trailing", "Trailing stop:")


# 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 print_epoch_details(
    results,
    total_epochs: int,
    print_json: bool,
    no_header: bool = False,
    header_str: str = None,
) -> None:
    """
    Display details of the hyperopt result
    """
    params = results.get("params_details", {})

    # Default header string
    if header_str is None:
        header_str = "Best result"

    if not no_header:
        explanation_str = Hyperopt._format_explanation_string(results, total_epochs)
        print(f"\n{header_str}:\n\n{explanation_str}\n")

    if print_json:
        result_dict: Dict = {}
        for s in ["buy", "sell", "roi", "stoploss", "trailing"]:
            Hyperopt._params_update_for_json(result_dict, params, s)
        print(
            rapidjson.dumps(result_dict, default=str, number_mode=rapidjson.NM_NATIVE)
        )

    else:
        Hyperopt._params_pretty_print(params, "buy", "Buy hyperspace params:")
        Hyperopt._params_pretty_print(params, "sell", "Sell hyperspace params:")
        Hyperopt._params_pretty_print(params, "roi", "ROI table:")
        Hyperopt._params_pretty_print(params, "stoploss", "Stoploss:")
        Hyperopt._params_pretty_print(params, "trailing", "Trailing stop:")