Allow Strategy subclassing in different files by enabling local imports

This commit is contained in:
Matthias 2022-03-20 13:07:06 +01:00
parent fcec071a08
commit 49e087df5b
3 changed files with 45 additions and 24 deletions

View File

@ -164,16 +164,15 @@ class MyAwesomeStrategy2(MyAwesomeStrategy):
Both attributes and methods may be overridden, altering behavior of the original strategy in a way you need.
!!! Note "Parent-strategy in different files"
If you have the parent-strategy in a different file, you'll need to add the following to the top of your "child"-file to ensure proper loading, otherwise freqtrade may not be able to load the parent strategy correctly.
If you have the parent-strategy in a different file, you can still import the strategy.
Assuming `myawesomestrategy.py` is the filename, and `MyAwesomeStrategy` the strategy you need to import:
``` python
import sys
from pathlib import Path
sys.path.append(str(Path(__file__).parent))
from myawesomestrategy import MyAwesomeStrategy
```
This is the recommended way to derive strategies to avoid problems with hyperopt parameter files.
## Embedding Strategies
Freqtrade provides you with an easy way to embed the strategy into your configuration file.

View File

@ -6,6 +6,7 @@ This module load custom objects
import importlib.util
import inspect
import logging
import sys
from pathlib import Path
from typing import Any, Dict, Iterator, List, Optional, Tuple, Type, Union
@ -15,6 +16,22 @@ from freqtrade.exceptions import OperationalException
logger = logging.getLogger(__name__)
class PathModifier:
def __init__(self, path: Path):
self.path = path
def __enter__(self):
"""Inject path to allow importing with relative imports."""
sys.path.insert(0, str(self.path))
return self
def __exit__(self, exc_type, exc_val, exc_tb):
"""Undo insertion of local path."""
str_path = str(self.path)
if str_path in sys.path:
sys.path.remove(str_path)
class IResolver:
"""
This class contains all the logic to load custom classes
@ -57,7 +74,9 @@ class IResolver:
# Generate spec based on absolute path
# Pass object_name as first argument to have logging print a reasonable name.
spec = importlib.util.spec_from_file_location(object_name or "", str(module_path))
with PathModifier(module_path.parent):
spec = importlib.util.spec_from_file_location(module_path.stem or "", str(module_path))
if not spec:
return iter([None])
@ -75,8 +94,11 @@ class IResolver:
name, obj in inspect.getmembers(
module, inspect.isclass) if ((object_name is None or object_name == name)
and issubclass(obj, cls.object_type)
and obj is not cls.object_type)
and obj is not cls.object_type
and obj.__module__ == module_path.stem or ""
)
)
# The __module__ check ensures we only use strategies that are defined in this folder.
return valid_objects_gen
@classmethod

View File

@ -7,7 +7,7 @@ from pandas import DataFrame
import freqtrade.vendor.qtpylib.indicators as qtpylib
from freqtrade.persistence import Trade
from freqtrade.strategy.interface import IStrategy
from freqtrade.strategy import IStrategy
class StrategyTestV2(IStrategy):