regex._regex_core.error: bad escape \w at position 8

[captainIT]

          **在 Windows  环境中 如果有个环境变量包含windows路径，如下：**

import regex as re
regexp = '\\{\\{[\\\'\\"]?\\s*\\$WORK_DIR\\s*\\:\\s*None\\s*[\\\'\\"]?\\}\\}'
value = "D:\\666\\work_dir"
config_file='_work_dir = {{"$DLP_WORK_DIR:None"}}'
config_file = re.sub(regexp, value, config_file)

返回错误
regex._regex_core.error: bad escape \w at position 8

Originally posted by @captainIT in #744 (comment)

[mm-assistant]

We recommend using English or English & Chinese for issues so that we could have broader discussion.

[HAOCHENYE]

Will replace value with rf'{value}' help you?

[captainIT]

value 是通过环境变量设置的字符串

代码来源如下
mmengine\config\config.py

 @staticmethod
def _substitute_env_variables(filename: str, temp_config_name: str):
      with open(filename, encoding='utf-8') as f:
            config_file = f.read()
        regexp = r'\{\{[\'\"]?\s*\$(\w+)\s*\:\s*(\S*?)\s*[\'\"]?\}\}'
        keys = re.findall(regexp, config_file)
        env_variables = dict()
        for var_name, value in keys:
            regexp = r'\{\{[\'\"]?\s*\$' + var_name + r'\s*\:\s*' \
                + value + r'\s*[\'\"]?\}\}'
            if var_name in os.environ:
                value = os.environ[var_name]
                env_variables[var_name] = value
                print_log(
                    f'Using env variable `{var_name}` with value of '
                    f'{value} to replace item in config.',
                    logger='current')
            if not value:
                raise KeyError(f'`{var_name}` cannot be found in `os.environ`.'
                               f' Please set `{var_name}` in environment or '
                               'give a default value.')
            config_file = re.sub(regexp, value, config_file)

        with open(temp_config_name, 'w', encoding='utf-8') as tmp_config_file:
            tmp_config_file.write(config_file)
        return env_variables

[HAOCHENYE]

I mean you can try to replace value with rf'{value}' in this line

mmengine/mmengine/config/config.py

Line 351 in 4a9e379

regexp = r'\{\{[\'\"]?\s*\$' + var_name + r'\s*\:\s*' \

If it helps, we could enhance this code snippet ASAP

[captainIT]

import regex as re
regexp = '\\{\\{[\\\'\\"]?\\s*\\$DLP_WORK_DIR\\s*\\:\\s*None\\s*[\\\'\\"]?\\}\\}'
value1 = rf"D:\\666\\work_dir"
value2 = "D:\\666\\work_dir"
value2 = rf'{value2}'
config_file='_work_dir = {{"$DLP_WORK_DIR:None"}}'
config_file1 = re.sub(regexp, value1, config_file)
print(f"========config_file1:===:{config_file1}:===========")
config_file2 = re.sub(regexp, value2, config_file)
print(f"========config_file2:===:{config_file2}:===========")

第一个可以正常输出
========config_file1:===:_work_dir = D:\666\work_dir:===========
第二个报错 regex._regex_core.error: bad escape \w at position 8

[HAOCHENYE]

Emmm, maybe value = value.encode('unicode_escape').decode() could help, but we need to study whether this modification is general enough for all platforms.