[SQUASH] Address PR comments.

* Split Parameter into IntParameter/FloatParameter/CategoricalParameter.
* Rename IHyperStrategy to HyperStrategyMixin and use it as mixin.
* --hyperopt parameter is now optional if strategy uses HyperStrategyMixin.
* Use OperationalException() instead of asserts.

freqtrade/optimize/hyperopt.py

@@ -23,6 +23,7 @@ from pandas import DataFrame
 from freqtrade.constants import DATETIME_PRINT_FORMAT, LAST_BT_RESULT_FN
 from freqtrade.data.converter import trim_dataframe
 from freqtrade.data.history import get_timerange
+from freqtrade.exceptions import OperationalException
 from freqtrade.misc import file_dump_json, plural
 from freqtrade.optimize.backtesting import Backtesting
 # Import IHyperOpt and IHyperOptLoss to allow unpickling classes from these modules
@@ -68,7 +69,11 @@ class Hyperopt:
 
         self.backtesting = Backtesting(self.config)
 
-        if self.config['hyperopt'] == 'HyperOptAuto':
+        if not self.config.get('hyperopt'):
+            if not getattr(self.backtesting.strategy, 'HYPER_STRATEGY', False):
+                raise OperationalException('Strategy is not auto-hyperoptable. Specify --hyperopt '
+                                           'parameter or add HyperStrategyMixin mixin to your '
+                                           'strategy class.')
             self.custom_hyperopt = HyperOptAuto(self.config)
         else:
             self.custom_hyperopt = HyperOptResolver.load_hyperopt(self.config)

freqtrade/optimize/hyperopt_auto.py

@@ -1,7 +1,7 @@
 """
 HyperOptAuto class.
-This module implements a convenience auto-hyperopt class, which can be used together with strategies that implement
-IHyperStrategy interface.
+This module implements a convenience auto-hyperopt class, which can be used together with strategies
+ that implement IHyperStrategy interface.
 """
 from typing import Any, Callable, Dict, List
 from pandas import DataFrame
@@ -13,26 +13,31 @@ from freqtrade.optimize.hyperopt_interface import IHyperOpt
 # noinspection PyUnresolvedReferences
 class HyperOptAuto(IHyperOpt):
     """
-    This class delegates functionality to Strategy(IHyperStrategy) and Strategy.HyperOpt classes. Most of the time
-    Strategy.HyperOpt class would only implement indicator_space and sell_indicator_space methods, but other hyperopt
-    methods can be overridden as well.
+    This class delegates functionality to Strategy(IHyperStrategy) and Strategy.HyperOpt classes.
+     Most of the time Strategy.HyperOpt class would only implement indicator_space and
+     sell_indicator_space methods, but other hyperopt methods can be overridden as well.
     """
+
     def buy_strategy_generator(self, params: Dict[str, Any]) -> Callable:
-        assert hasattr(self.strategy, 'enumerate_parameters'), 'Strategy must inherit from IHyperStrategy.'
+        if not getattr(self.strategy, 'HYPER_STRATEGY', False):
+            raise OperationalException('Strategy must inherit from IHyperStrategy.')
 
         def populate_buy_trend(dataframe: DataFrame, metadata: dict):
             for attr_name, attr in self.strategy.enumerate_parameters('buy'):
                 attr.value = params[attr_name]
             return self.strategy.populate_buy_trend(dataframe, metadata)
+
         return populate_buy_trend
 
     def sell_strategy_generator(self, params: Dict[str, Any]) -> Callable:
-        assert hasattr(self.strategy, 'enumerate_parameters'), 'Strategy must inherit from IHyperStrategy.'
+        if not getattr(self.strategy, 'HYPER_STRATEGY', False):
+            raise OperationalException('Strategy must inherit from IHyperStrategy.')
 
         def populate_buy_trend(dataframe: DataFrame, metadata: dict):
             for attr_name, attr in self.strategy.enumerate_parameters('sell'):
                 attr.value = params[attr_name]
             return self.strategy.populate_sell_trend(dataframe, metadata)
+
         return populate_buy_trend
 
     def _get_func(self, name) -> Callable:
@@ -49,7 +54,8 @@ class HyperOptAuto(IHyperOpt):
             return default_func
 
     def _generate_indicator_space(self, category):
-        assert hasattr(self.strategy, 'enumerate_parameters'), 'Strategy must inherit from IHyperStrategy.'
+        if not getattr(self.strategy, 'HYPER_STRATEGY', False):
+            raise OperationalException('Strategy must inherit from IHyperStrategy.')
 
         for attr_name, attr in self.strategy.enumerate_parameters(category):
             yield attr.get_space(attr_name)

freqtrade/optimize/hyperopt_interface.py

@@ -5,15 +5,14 @@ This module defines the interface to apply for hyperopt
 import logging
 import math
 from abc import ABC
-from typing import Any, Callable, Dict, List
+from typing import Any, Callable, Dict, List, Union
 
 from skopt.space import Categorical, Dimension, Integer, Real
 
 from freqtrade.exceptions import OperationalException
 from freqtrade.exchange import timeframe_to_minutes
 from freqtrade.misc import round_dict
-from freqtrade.strategy import IStrategy
-
+from freqtrade.strategy import IStrategy, HyperStrategyMixin
 
 logger = logging.getLogger(__name__)
 
@@ -35,7 +34,7 @@ class IHyperOpt(ABC):
     """
     ticker_interval: str  # DEPRECATED
     timeframe: str
-    strategy: IStrategy
+    strategy: Union[IStrategy, HyperStrategyMixin]
 
     def __init__(self, config: dict) -> None:
         self.config = config