freqtrade_origin/freqtrade/resolvers/exchange_resolver.py
2019-06-22 16:52:14 +02:00

57 lines
1.7 KiB
Python

"""
This module loads custom exchanges
"""
import logging
from freqtrade.exchange import Exchange
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) -> None:
"""
Load the custom class from config parameter
:param config: configuration dictionary
"""
exchange_name = exchange_name.title()
try:
self.exchange = self._load_exchange(exchange_name, kwargs={'config': config})
except ImportError:
logger.info(
f"No {exchange_name} specific subclass found. Using the generic class instead.")
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['config'])
if exchange:
logger.info("Using resolved exchange %s", exchange_name)
return exchange
except AttributeError:
# Pass and raise ImportError instead
pass
raise ImportError(
"Impossible to load Exchange '{}'. This class does not exist"
" or contains Python code errors".format(exchange_name)
)