# Buggy code
def adjust(self, pairs) -> list:
    """
    Filters out and sorts "pairs" according to Edge calculated pairs
    """
    final = []
    for pair, info in self._cached_pairs.items():
        if (
            info.expectancy > float(self.edge_config.get("minimum_expectancy", 0.2))
            and info.winrate > float(self.edge_config.get("minimum_winrate", 0.60))
            and pair in pairs
        ):
            final.append(pair)

    if self._final_pairs != final:
        self._final_pairs = final
        if self._final_pairs:
            logger.info(
                "Minimum expectancy and minimum winrate are met only for %s,"
                " so other pairs are filtered out.",
                self._final_pairs,
            )
        else:
            logger.info(
                "Edge removed all pairs as no pair with minimum expectancy "
                "and minimum winrate was found !"
            )

    return self._final_pairs


# 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 adjust(self, pairs: List[str]) -> list:
    """
    Filters out and sorts "pairs" according to Edge calculated pairs
    """
    final = []
    for pair, info in self._cached_pairs.items():
        if (
            info.expectancy > float(self.edge_config.get("minimum_expectancy", 0.2))
            and info.winrate > float(self.edge_config.get("minimum_winrate", 0.60))
            and pair in pairs
        ):
            final.append(pair)

    if self._final_pairs != final:
        self._final_pairs = final
        if self._final_pairs:
            logger.info(
                "Minimum expectancy and minimum winrate are met only for %s,"
                " so other pairs are filtered out.",
                self._final_pairs,
            )
        else:
            logger.info(
                "Edge removed all pairs as no pair with minimum expectancy "
                "and minimum winrate was found !"
            )

    return self._final_pairs