stable/freqtrade/strategy/strategy_wrapper.py
2022-05-24 06:54:16 +02:00

47 lines
1.5 KiB
Python

import logging
from copy import deepcopy
from functools import wraps
from typing import Any, Callable, TypeVar, cast
from freqtrade.exceptions import StrategyError
logger = logging.getLogger(__name__)
F = TypeVar('F', bound=Callable[..., Any])
def strategy_safe_wrapper(f: F, message: str = "", default_retval=None, supress_error=False) -> F:
"""
Wrapper around user-provided methods and functions.
Caches all exceptions and returns either the default_retval (if it's not None) or raises
a StrategyError exception, which then needs to be handled by the calling method.
"""
@wraps(f)
def wrapper(*args, **kwargs):
try:
if 'trade' in kwargs:
# Protect accidental modifications from within the strategy
kwargs['trade'] = deepcopy(kwargs['trade'])
return f(*args, **kwargs)
except ValueError as error:
logger.warning(
f"{message}"
f"Strategy caused the following exception: {error}"
f"{f}"
)
if default_retval is None and not supress_error:
raise StrategyError(str(error)) from error
return default_retval
except Exception as error:
logger.exception(
f"{message}"
f"Unexpected error {error} calling {f}"
)
if default_retval is None and not supress_error:
raise StrategyError(str(error)) from error
return default_retval
return cast(F, wrapper)