[Bug] Issue with Python Logging in Jaclang (Version 0.7.18)

[kashmithnisakya]

Description:

I am trying to integrate Python logging in Jaclang, but I’ve encountered an issue where the log file is not created as expected.

Here’s the Python code I tested:

import logging

# Configure logging to write to a file and overwrite it each time
logging.basicConfig(
   filename='logfile.log',
   level=logging.INFO,
   format='%(asctime)s - %(levelname)s - %(message)s',
   filemode='w'  # 'w' mode ensures overwriting the file
)

# Example log entries
logging.info('This is an info message.')
logging.error('This is an error message.')

This Python code works as intended and creates a logfile.log with the following output:

2024-10-14 16:57:07,873 - INFO - This is an info message.
2024-10-14 16:57:07,873 - ERROR - This is an error message. 

However, when I try to do the same in Jac (version 0.7.18) using the following Jac code, the log file is not created:

import:py logging;

with entry:__main__{
    logging.basicConfig(
        filename='logfile.log', 
        level=logging.INFO, 
        format='%(asctime)s - %(levelname)s - %(message)s',
        filemode='w'
    );

    logging.info('This is an info message.');
    logging.error('This is an error message.');
}

Expected Behavior:

• The logfile.log should be created, and it should contain the log entries as specified in the code.

Actual Behavior:

• No log file is created.

Steps to Reproduce:

1. Run the provided Jac code.
2. Observe that no log file is generated.

Environment:

• Jac Version: 0.7.18

Could you please look into why this issue is occurring in Jac and why it is not creating the log file as it does with the Python implementation?

Thank you!

[kugesan1105]

@marsninja
yes, I’ve encountered the same problem where the log messages are printed to the terminal instead of being written to a file as expected

After looking into the jac_gen file, I suspect the issue might be with how jac_import is handling the logging module.

from __future__ import annotations
from jaclang import jac_import as __jac_import__
import typing as _jac_typ
if _jac_typ.TYPE_CHECKING:
    import logging
else:
    logging, = __jac_import__(target='logging', base_path=__file__, lng='py', absorb=False, mdl_alias=None, items={})

[ypkang]

have you tried using the logger instance to log? something like this

import logging
logger = logging.getLogger(__name__)
logging.basicConfig(filename='example.log', encoding='utf-8', level=logging.DEBUG)
logger.debug('This message should go to the log file')
logger.info('So should this')
logger.warning('And this, too')
logger.error('And non-ASCII stuff, too, like Øresund and Malmö')

[kugesan1105]

Hey @ypkang,
I tried the logger instance approach as suggested, but the issue persisted—log files were not being created, and messages were still printed to the screen.

@kashmithnisakya
However, I then tried using a FileHandler directly with the logger, and that worked! But Logs are now output to both the terminal and the file:

import:py logging;

with entry:__main__{
    logger = logging.getLogger(__name__);
    logger.setLevel(logging.INFO);
    # Create file handler and set level
    file_handler = logging.FileHandler('logfile_jac.log', mode='w');
    file_handler.setFormatter(logging.Formatter('%(asctime)s - %(levelname)s - %(message)s'));
    # Clear any pre-existing handlers
    if logger.hasHandlers(){
        logger.handlers.clear();
    }
    # Add file handler to logger
    logger.addHandler(file_handler);
    logger.info('This is an info message.');
    logger.error('This is an error message.');
}