stable/freqtrade/resolvers/exchange_resolver.py
hroff-1902 3cf95f9f6c
Merge pull request #2369 from freqtrade/disable_exchangevalidate
Allow skipping of exchange validation
2019-10-22 12:22:48 +03:00

61 lines
2.0 KiB
Python

"""
This module loads custom exchanges
"""
import logging
from freqtrade.exchange import Exchange, MAP_EXCHANGE_CHILDCLASS
import freqtrade.exchange as exchanges
from freqtrade.resolvers import IResolver
logger = logging.getLogger(__name__)
class ExchangeResolver(IResolver):
"""
This class contains all the logic to load a custom exchange class
"""
__slots__ = ['exchange']
def __init__(self, exchange_name: str, config: dict, validate: bool = True) -> None:
"""
Load the custom class from config parameter
:param config: configuration dictionary
"""
# Map exchange name to avoid duplicate classes for identical exchanges
exchange_name = MAP_EXCHANGE_CHILDCLASS.get(exchange_name, exchange_name)
exchange_name = exchange_name.title()
try:
self.exchange = self._load_exchange(exchange_name, kwargs={'config': config,
'validate': validate})
except ImportError:
logger.info(
f"No {exchange_name} specific subclass found. Using the generic class instead.")
if not hasattr(self, "exchange"):
self.exchange = Exchange(config)
def _load_exchange(
self, exchange_name: str, kwargs: dict) -> Exchange:
"""
Loads the specified exchange.
Only checks for exchanges exported in freqtrade.exchanges
:param exchange_name: name of the module to import
:return: Exchange instance or None
"""
try:
ex_class = getattr(exchanges, exchange_name)
exchange = ex_class(**kwargs)
if exchange:
logger.info(f"Using resolved exchange '{exchange_name}'...")
return exchange
except AttributeError:
# Pass and raise ImportError instead
pass
raise ImportError(
f"Impossible to load Exchange '{exchange_name}'. This class does not exist "
"or contains Python code errors."
)