content: from __future__ import annotations
  
  import argparse
  import ast
  import json
  import os
  import os.path as osp
  import re
  import shutil
  import sys
  import tempfile
  from copy import deepcopy
  from importlib import import_module
  
  import yaml
  
  # from ..utils.easydict import EasyDict
  from utils.easydict import EasyDict
  
  __all__ = ["Config", "pretty_text"]
  
  
  BASE_KEY = "_base_"
  # BASE_CONFIG = {"OUTPUT_DIR": "./workspace", "SESSION": "base", "LOG_FILE": "log.txt"}
  BASE_CONFIG = {}
  
  cfg = None
  
  
  class Config(object):
      """config"""
  
      @classmethod
      def pretty_text(cls, cfg: dict, indent=2) -> str:
          """format dict to a string
  
          Args:
              cfg (EasyDict): the params.
  
          Returns: The string to display.
  
          """
          msg = "{\n"
          for i, (k, v) in enumerate(cfg.items()):
              if isinstance(v, dict):
                  v = cls.pretty_text(v, indent + 4)
              spaces = " " * indent
              msg += spaces + "{}: {}".format(k, v)
              if i == len(cfg) - 1:
                  msg += " }"
              else:
                  msg += "\n"
          return msg
  
      @classmethod
      def dump(cls, cfg, savepath=None):
          """dump cfg to `json` file.
  
          Args:
              cfg (dict): The dict to dump.
              savepath (str): The filepath to save the dumped dict.
  
          Returns: TODO
  
          """
          if savepath is None:
              savepath = osp.join(cfg.WORKSPACE, "config.json")
          json.dump(cfg, open(savepath, "w"), indent=2)
  
      @classmethod
      def get_config(cls, default_config: dict = None):
          """get a `Config` instance.
  
          Args:
              default_config (dict): The default config. `default_config` will be overrided
                  by config file `--cfg`, `--cfg` will be overrided by commandline args.
  
          Returns: an EasyDict.
          """
          global cfg
          if cfg is not None:
              return cfg
  
          # define arg parser.
          parser = argparse.ArgumentParser()
          # parser.add_argument("--cfg", help="load configs from yaml file", default="", type=str)
          parser.add_argument(
              "config_file", help="the configuration file to load. support: .yaml, .json, .py"
          )
          parser.add_argument(
              "opts",
              default=None,
              nargs="*",
              help="overrided configs. List. Format: 'key1 name1 key2 name2'",
          )
          args = parser.parse_args()
  
          cfg = EasyDict(BASE_CONFIG)
          if osp.isfile(args.config_file):
              cfg_from_file = cls.from_file(args.config_file)
              cfg = merge_a_into_b(cfg_from_file, cfg)
          cfg = cls.merge_list(cfg, args.opts)
          cfg = eval_dict_leaf(cfg)
  
          # update some keys to make them show at the last
          for k in BASE_CONFIG:
              cfg[k] = cfg.pop(k)
          return cfg
  
      @classmethod
      def from_file(cls, filepath: str) -> EasyDict:
          """Build config from file. Supported filetypes: `.py`,`.yaml`,`.json`.
  
          Args:
              filepath (str): The config file path.
  
          Returns: TODO
  
          """
          filepath = osp.abspath(osp.expanduser(filepath))
          if not osp.isfile(filepath):
              raise IOError(f"File does not exist: {filepath}")
          if filepath.endswith(".py"):
              sys.path.insert(0, osp.dirname(filepath))
              mod = import_module(osp.splitext(osp.basename(filepath))[0])
              cfg_dict = {
                  name: value
                  for name, value in mod.__dict__.items()
                  if not name.startswith("__")
              }
  
          elif filepath.endswith((".yml", ".yaml")):
              cfg_dict = yaml.load(open(filepath, "r"), Loader=yaml.Loader)
          elif filepath.endswith(".json"):
              cfg_dict = json.load(open(filepath, "r"))
          else:
              raise IOError("Only py/yml/yaml/json type are supported now!")
  
          cfg_text = filepath + "\n"
          with open(filepath, "r") as f:
              cfg_text += f.read()
  
          if BASE_KEY in cfg_dict:  # load configs in `BASE_KEY`
              cfg_dir = osp.dirname(filepath)
              base_filename = cfg_dict.pop(BASE_KEY)
              base_filename = (
                  base_filename if isinstance(base_filename, list) else [base_filename]
              )
  
              cfg_dict_list = list()
              for f in base_filename:
                  _cfg_dict = Config.from_file(osp.join(cfg_dir, f))
                  cfg_dict_list.append(_cfg_dict)
  
              base_cfg_dict = dict()
              for c in cfg_dict_list:
                  if len(base_cfg_dict.keys() & c.keys()) > 0:
                      raise KeyError("Duplicate key is not allowed among bases")
                  base_cfg_dict.update(c)
  
              cfg_dict = merge_a_into_b(cfg_dict, base_cfg_dict)
  
          return EasyDict(cfg_dict)
  
      @classmethod
      def merge_list(cls, cfg, opts: list):
          """merge commandline opts.
  
          Args:
              cfg: (dict): The config to be merged.
              opts (list): The list to merge. Format: [key1, name1, key2, name2,...].
                  The keys can be nested. For example, ["a.b", v] will be considered
                  as `dict(a=dict(b=v))`.
  
          Returns: dict.
  
          """
          assert len(opts) % 2 == 0, f"length of opts must be even. Got: {opts}"
          for i in range(0, len(opts), 2):
              full_k, v = opts[i], opts[i + 1]
              keys = full_k.split(".")
              sub_d = cfg
              for i, k in enumerate(keys):
                  if not hasattr(sub_d, k):
                      raise ValueError(f"The key {k} not exist in the config. Full key:{full_k}")
                  if i != len(keys) - 1:
                      sub_d = sub_d[k]
                  else:
                      sub_d[k] = v
          return cfg
  
  
  def merge_a_into_b(a, b, inplace=False):
      """The values in a will override values in b.
  
      Args:
          a (dict): source dict.
          b (dict): target dict.
  
      Returns: dict. recursively merge dict a into dict b.
  
      """
      if not inplace:
          b = deepcopy(b)
      for key in a:
          if key in b:
              if isinstance(a[key], dict) and isinstance(b[key], dict):
                  b[key] = merge_a_into_b(a[key], b[key], inplace=True)
              else:
                  b[key] = a[key]
          else:
              b[key] = a[key]
      return b
  
  
  def eval_dict_leaf(d, orig_dict=None):
      """eval values of dict leaf.
  
      Args:
          d (dict): The dict to eval.
  
      Returns: dict.
  
      """
      if orig_dict is None:
          orig_dict = d
      for k, v in d.items():
          if not isinstance(v, dict):
              d[k] = eval_string(v, orig_dict)
          else:
              eval_dict_leaf(v, orig_dict)
      return d
  
  
  def eval_string(string, d):
      """automatically evaluate string to corresponding types.
  
      For example:
          not a string  -> return the original input
          '0'  -> 0
          '0.2' -> 0.2
          '[0, 1, 2]' -> [0,1,2]
          'eval(1+2)' -> 3
          'eval(range(5))' -> [0,1,2,3,4]
          '${a}' -> d.a
  
  
  
      Args:
          string (str): The value to evaluate.
          d (dict): The
  
      Returns: the corresponding type
  
      """
      if not isinstance(string, str):
          return string
      # if len(string) > 1 and string[0] == "[" and string[-1] == "]":
      #     return eval(string)
      if string[0:5] == "eval(":
          return eval(string[5:-1])
  
      s0 = string
      s1 = re.sub(r"\${(.*)}", r"d.\1", s0)
      if s1 != s0:
          while s1 != s0:
              s0 = s1
              s1 = re.sub(r"\${(.*)}", r"d.\1", s0)
          return eval(s1)
  
      try:
          v = ast.literal_eval(string)
      except:
          v = string
      return v
  