stable/freqtrade/resolvers/exchange_resolver.py
2019-02-17 14:42:55 +01:00

58 lines
2.0 KiB
Python

"""
This module loads custom exchanges
"""
import logging
from pathlib import Path
from freqtrade.exchange import Exchange
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, freqtrade, config: dict) -> None:
"""
Load the custom class from config parameter
:param config: configuration dictionary or None
"""
self.exchange = self._load_exchange(exchange_name, kwargs={'freqtrade': freqtrade,
'config': config})
def _load_exchange(
self, exchange_name: str, kwargs: dict) -> Exchange:
"""
Search and loads the specified exchange.
:param exchange_name: name of the module to import
:param extra_dir: additional directory to search for the given exchange
:return: Exchange instance or None
"""
current_path = Path(__file__).parent.parent.joinpath('exchange').resolve()
abs_paths = [
current_path.parent.parent.joinpath('user_data/exchange'),
current_path,
]
for _path in abs_paths:
try:
exchange = self._search_object(directory=_path, object_type=Exchange,
object_name=exchange_name,
kwargs=kwargs)
if exchange:
logger.info('Using resolved exchange %s from \'%s\'', exchange_name, _path)
return exchange
except FileNotFoundError:
logger.warning('Path "%s" does not exist', _path.relative_to(Path.cwd()))
raise ImportError(
"Impossible to load Exchange '{}'. This class does not exist"
" or contains Python code errors".format(exchange_name)
)