microsoft/qlib · error · FileNotFoundError

file "{}" does not exist

Error message

file "{}" does not exist

What it means

parse_backtest_config (qlib/rl/contrib/naive_config_parser.py:28) loads a qlib.rl backtest configuration from .py/.json/.yaml/.yml files. check_file_exist first resolves the path to an absolute path and raises FileNotFoundError('file "<path>" does not exist') when os.path.isfile is false — i.e. the file is missing, is a directory, or the path is wrong.

Source

Thrown at qlib/rl/contrib/naive_config_parser.py:28

from ruamel.yaml import YAML

DELETE_KEY = "_delete_"


def merge_a_into_b(a: dict, b: dict) -> dict:
    b = b.copy()
    for k, v in a.items():
        if isinstance(v, dict) and k in b:
            v.pop(DELETE_KEY, False)
            b[k] = merge_a_into_b(v, b[k])
        else:
            b[k] = v
    return b


def check_file_exist(filename: str, msg_tmpl: str = 'file "{}" does not exist') -> None:
    if not os.path.isfile(filename):
        raise FileNotFoundError(msg_tmpl.format(filename))


def parse_backtest_config(path: str) -> dict:
    abs_path = os.path.abspath(path)
    check_file_exist(abs_path)

    file_ext_name = os.path.splitext(abs_path)[1]
    if file_ext_name not in (".py", ".json", ".yaml", ".yml"):
        raise IOError("Only py/yml/yaml/json type are supported now!")

    with tempfile.TemporaryDirectory() as tmp_config_dir:
        with tempfile.NamedTemporaryFile(dir=tmp_config_dir, suffix=file_ext_name) as tmp_config_file:
            if platform.system() == "Windows":
                tmp_config_file.close()

            tmp_config_name = os.path.basename(tmp_config_file.name)
            shutil.copyfile(abs_path, tmp_config_file.name)

View on GitHub (pinned to 79633dd950)

Solutions

1. Verify the file exists with os.path.isfile(path) before calling parse_backtest_config
2. Use an absolute path (e.g. Path(__file__).parent / 'config.yaml') instead of a cwd-relative path
3. Check for typos in the filename and ensure you are not passing a directory
4. Download/restore the config file if it is part of examples/data not shipped with the package

Example fix

# before
config = parse_backtest_config('examples/rl/config.yaml')  # may not exist relative to cwd

# after
from pathlib import Path
cfg_path = Path(__file__).resolve().parent / 'config.yaml'
assert cfg_path.is_file(), f'missing config: {cfg_path}'
config = parse_backtest_config(str(cfg_path))

import os
abs_path = os.path.abspath(path)
if not os.path.isfile(abs_path):
    raise FileNotFoundError(f'backtest config not found: {abs_path}')

try:
    cfg = parse_backtest_config(path)
except FileNotFoundError as e:
    raise ValueError(f'check cwd={os.getcwd()} and the config path') from e

When it happens

Trigger: Calling parse_backtest_config(path) where path points to a nonexistent file (typo, wrong working directory since the path is made absolute relative to cwd, or a directory path); passing a relative path from a different working directory.

Common situations: Running RL backtest examples with example config paths relative to the repo root while cwd is elsewhere; moved/renamed config files; missing 'default_config.yaml' in examples; typos in CLI arguments.

Related errors

• Only py/yml/yaml/json type are supported now!
• method {method} is not supported!
• This type of input {rtype} is not supported
• Can't find the BASE_CONFIG file: {base_config_path}
• Cannot find config file {}

AI-assisted analysis of microsoft/qlib@79633dd950 (2026-08-15). Data as JSON: /api/errors/3ec4596334e0e852. Report an issue: GitHub.