Source code for deeppavlov.core.common.metrics_registry

import importlib
from pathlib import Path
import json
from typing import List, Callable, Any

from deeppavlov.core.common.errors import ConfigError
from deeppavlov.core.common.log import get_logger


log = get_logger(__name__)

_registry_path = Path(__file__).parent / 'metrics_registry.json'
if _registry_path.exists():
    with _registry_path.open(encoding='utf-8') as f:
        _REGISTRY = json.load(f)
else:
    _REGISTRY = {}


def fn_from_str(name: str) -> Callable[..., Any]:
    """Returns a function object with the name given in string."""
    try:
        module_name, fn_name = name.split(':')
    except ValueError:
        raise ConfigError('Expected function description in a `module.submodules:function_name` form, but got `{}`'
                          .format(name))

    return getattr(importlib.import_module(module_name), fn_name)


def register_metric(metric_name: str) -> Callable[..., Any]:
    """Decorator for metric registration."""
    def decorate(fn):
        fn_name = fn.__module__ + ':' + fn.__name__
        if metric_name in _REGISTRY and _REGISTRY[metric_name] != fn_name:
            log.warning('"{}" is already registered as a metric name, the old function will be ignored'
                        .format(metric_name))
        _REGISTRY[metric_name] = fn_name
        return fn
    return decorate


def get_metrics_by_names(names: list) -> List[Callable[..., Any]]:
    """Returns a list of metric callables with corresponding names."""
    not_found = [name for name in names if name not in _REGISTRY]
    if not_found:
        raise ConfigError('Names {} are not registered as metrics'.format(not_found))
    return [fn_from_str(_REGISTRY[name]) for name in names]