Add output to file capability

[borntyping]

Add output to file capability

[borntyping]

Could you provide an example of what you're trying to do or why it would be useful to output coloured messages to a file?

[brey]

It is not really about coloured output. I have added an additional file handler to the logger created by color log based on logging ...

import colorlog, logging

handler = colorlog.StreamHandler()
handler.setFormatter(colorlog.ColoredFormatter(
	'%(log_color)s%(levelname)s:%(name)s:%(message)s'))

logger = colorlog.getLogger('example')
logger.addHandler(handler)
logger.setLevel(logging.DEBUG)

file_handler = logging.StreamHandler('test.log')
fformatter = logging.Formatter('%(levelname)-8s %(asctime)s:%(name)s:%(message)s')
file_handler.setFormatter(fformatter)
logger.addHandler(file_handler)

The idea is to output on screen and to a file as the same time (it works with logging). However, when I run

logger.info('info')

I get

INFO:example:info
--- Logging error ---
Traceback (most recent call last):
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/logging/__init__.py", line 1037, in emit
    stream.write(msg + self.terminator)
AttributeError: 'str' object has no attribute 'write'
Call stack:
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/runpy.py", line 193, in _run_module_as_main
    "__main__", mod_spec)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/ipykernel_launcher.py", line 16, in <module>
    app.launch_new_instance()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/traitlets/config/application.py", line 658, in launch_instance
    app.start()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/ipykernel/kernelapp.py", line 563, in start
    self.io_loop.start()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/platform/asyncio.py", line 148, in start
    self.asyncio_loop.run_forever()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/asyncio/base_events.py", line 539, in run_forever
    self._run_once()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/asyncio/base_events.py", line 1775, in _run_once
    handle._run()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/asyncio/events.py", line 88, in _run
    self._context.run(self._callback, *self._args)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/ioloop.py", line 690, in <lambda>
    lambda f: self._run_callback(functools.partial(callback, future))
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/ioloop.py", line 743, in _run_callback
    ret = callback()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/gen.py", line 787, in inner
    self.run()
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/gen.py", line 748, in run
    yielded = self.gen.send(value)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/ipykernel/kernelbase.py", line 365, in process_one
    yield gen.maybe_future(dispatch(*args))
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/gen.py", line 209, in wrapper
    yielded = next(result)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/ipykernel/kernelbase.py", line 272, in dispatch_shell
    yield gen.maybe_future(handler(stream, idents, msg))
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/gen.py", line 209, in wrapper
    yielded = next(result)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/ipykernel/kernelbase.py", line 542, in execute_request
    user_expressions, allow_stdin,
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/tornado/gen.py", line 209, in wrapper
    yielded = next(result)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/ipykernel/ipkernel.py", line 294, in do_execute
    res = shell.run_cell(code, store_history=store_history, silent=silent)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/ipykernel/zmqshell.py", line 536, in run_cell
    return super(ZMQInteractiveShell, self).run_cell(*args, **kwargs)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/IPython/core/interactiveshell.py", line 2855, in run_cell
    raw_cell, store_history, silent, shell_futures)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/IPython/core/interactiveshell.py", line 2881, in _run_cell
    return runner(coro)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/IPython/core/async_helpers.py", line 68, in _pseudo_sync_runner
    coro.send(None)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/IPython/core/interactiveshell.py", line 3058, in run_cell_async
    interactivity=interactivity, compiler=compiler, result=result)
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/IPython/core/interactiveshell.py", line 3249, in run_ast_nodes
    if (await self.run_code(code, result,  async_=asy)):
  File "/Users/brey/miniconda3/envs/pyPoseidon/lib/python3.7/site-packages/IPython/core/interactiveshell.py", line 3326, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-6-8d119e9a0d71>", line 1, in <module>
    logger.info('info')
Message: 'info'
Arguments: ()

.. so the screen part works but it can not output to file. I could use two different loggers but maybe there is a way to inherent the output functionality from logging...

[borntyping]

This is a problem with your use of the logging library, not colorlog.

In your example, you should use logging.FileHandler('test.log') instead of logging.StreamHandler(...).

FileHandler accepts a filename, but StreamHandler must be passed an open-file or file-like object. I hope this helps :)