stable/freqtrade/resolvers/iresolver.py
2018-11-24 20:14:08 +01:00

69 lines
2.4 KiB
Python

# pragma pylint: disable=attribute-defined-outside-init
"""
This module load custom objects
"""
import importlib.util
import inspect
import logging
import os
from typing import Optional, Dict, Type, Any
logger = logging.getLogger(__name__)
class IResolver(object):
"""
This class contains all the logic to load custom hyperopt class
"""
def __init__(self, object_type, config: Optional[Dict] = None) -> None:
"""
Load the custom class from config parameter
:param config: configuration dictionary or None
"""
config = config or {}
@staticmethod
def _get_valid_objects(object_type, module_path: str,
object_name: str) -> Optional[Type[Any]]:
"""
Returns a list of all possible objects for the given module_path of type oject_type
:param object_type: object_type (class)
:param module_path: absolute path to the module
:param object_name: Class name of the object
:return: Tuple with (name, class) or None
"""
# Generate spec based on absolute path
spec = importlib.util.spec_from_file_location('unknown', module_path)
module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(module) # type: ignore # importlib does not use typehints
valid_objects_gen = (
obj for name, obj in inspect.getmembers(module, inspect.isclass)
if object_name == name and object_type in obj.__bases__
)
return next(valid_objects_gen, None)
@staticmethod
def _search_object(directory: str, object_type, object_name: str,
kwargs: dict = {}) -> Optional[Any]:
"""
Search for the objectname in the given directory
:param directory: relative or absolute directory path
:return: object instance
"""
logger.debug('Searching for %s %s in \'%s\'', object_type.__name__, object_name, directory)
for entry in os.listdir(directory):
# Only consider python files
if not entry.endswith('.py'):
logger.debug('Ignoring %s', entry)
continue
obj = IResolver._get_valid_objects(
object_type, os.path.abspath(os.path.join(directory, entry)), object_name
)
if obj:
return obj(**kwargs)
return None