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_logger.py
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import functools
import inspect
import itertools
import logging
import re
import sys
import threading
import warnings
from collections import namedtuple
from inspect import isclass
from multiprocessing import current_process
from os.path import basename, normcase, splitext
from threading import current_thread
from colorama import AnsiToWin32
from . import _defaults
from ._better_exceptions import ExceptionFormatter
from ._datetime import now
from ._file_sink import FileSink
from ._get_frame import get_frame
from ._handler import Handler
from ._recattrs import ExceptionRecattr, FileRecattr, LevelRecattr, ProcessRecattr, ThreadRecattr
try:
from os import PathLike
except ImportError:
from pathlib import PurePath as PathLike
Level = namedtuple("Level", ["no", "color", "icon"])
start_time = now()
class Logger:
"""An object to dispatch logging messages to configured handlers.
The |Logger| is the core object of `loguru`, every logging configuration and usage pass through
a call to one of its methods. There is only one logger, so there is no need to retrieve one
before usage.
Once the ``logger`` is imported, it can be used to write messages about events happening in your
code. By reading the output logs of your application, you gain a better understanding of the
flow of your program and you more easily track and debug unexpected behaviors.
Handlers to which the logger sends log messages are added using the |add| method. Note that you
can use the |Logger| right after import as it comes pre-configured (logs are emitted to
|sys.stderr| by default). Messages can be logged with different severity levels and using braces
attributes like the |str.format| method do.
When a message is logged, a "record" is associated with it. This record is a dict which contains
several information about the logging context: time, function, file, line, thread, level...
It also contains the ``__name__`` of the module, this is why you don't need named loggers.
You should not instantiate a |Logger| by yourself, use ``from loguru import logger`` instead.
.. |Logger| replace:: :class:`~Logger`
.. |add| replace:: :meth:`~Logger.add()`
.. |remove| replace:: :meth:`~Logger.remove()`
.. |catch| replace:: :meth:`~Logger.catch()`
.. |bind| replace:: :meth:`~Logger.bind()`
.. |opt| replace:: :meth:`~Logger.opt()`
.. |log| replace:: :meth:`~Logger.log()`
.. |level| replace:: :meth:`~Logger.level()`
.. |enable| replace:: :meth:`~Logger.enable()`
.. |disable| replace:: :meth:`~Logger.disable()`
.. |str| replace:: :class:`str`
.. |int| replace:: :class:`int`
.. |bool| replace:: :class:`bool`
.. |tuple| replace:: :class:`tuple`
.. |list| replace:: :class:`list`
.. |dict| replace:: :class:`dict`
.. |str.format| replace:: :meth:`str.format()`
.. |Path| replace:: :class:`pathlib.Path`
.. |match.groupdict| replace:: :meth:`re.Match.groupdict()`
.. |Handler| replace:: :class:`logging.Handler`
.. |sys.stderr| replace:: :data:`sys.stderr`
.. |sys.exc_info| replace:: :func:`sys.exc_info()`
.. |time| replace:: :class:`datetime.time`
.. |datetime| replace:: :class:`datetime.datetime`
.. |timedelta| replace:: :class:`datetime.timedelta`
.. |open| replace:: :func:`open()`
.. |logging| replace:: :mod:`logging`
.. |Thread.run| replace:: :meth:`threading.Thread.run()`
.. |Exception| replace:: :class:`Exception`
.. |logger.trace| replace:: :meth:`logger.trace()<Logger.trace()>`
.. |logger.debug| replace:: :meth:`logger.debug()<Logger.debug()>`
.. |logger.info| replace:: :meth:`logger.info()<Logger.info()>`
.. |logger.success| replace:: :meth:`logger.success()<Logger.success()>`
.. |logger.warning| replace:: :meth:`logger.warning()<Logger.warning()>`
.. |logger.error| replace:: :meth:`logger.error()<Logger.error()>`
.. |logger.critical| replace:: :meth:`logger.critical()<Logger.critical()>`
.. |file-like object| replace:: ``file-like object``
.. _file-like object: https://docs.python.org/3/glossary.html#term-file-object
.. |class| replace:: ``class``
.. _class: https://docs.python.org/3/tutorial/classes.html
.. |function| replace:: ``function``
.. _function: https://docs.python.org/3/library/functions.html#callable
.. |re.Pattern| replace:: ``re.Pattern``
.. _re.Pattern: https://docs.python.org/3/library/re.html#re-objects
.. |re.Match| replace:: ``re.Match``
.. _re.Match: https://docs.python.org/3/library/re.html#match-objects
.. _Pendulum: https://pendulum.eustace.io/docs/#tokens
.. _ansimarkup: https://github.com/gvalkov/python-ansimarkup
.. _better_exceptions: https://github.com/Qix-/better-exceptions
.. _@sdispater: https://github.com/sdispater
.. _@gvalkov: https://github.com/gvalkov
.. _@Qix-: https://github.com/Qix-
"""
_levels = {
"TRACE": Level(
_defaults.LOGURU_TRACE_NO, _defaults.LOGURU_TRACE_COLOR, _defaults.LOGURU_TRACE_ICON
),
"DEBUG": Level(
_defaults.LOGURU_DEBUG_NO, _defaults.LOGURU_DEBUG_COLOR, _defaults.LOGURU_DEBUG_ICON
),
"INFO": Level(
_defaults.LOGURU_INFO_NO, _defaults.LOGURU_INFO_COLOR, _defaults.LOGURU_INFO_ICON
),
"SUCCESS": Level(
_defaults.LOGURU_SUCCESS_NO,
_defaults.LOGURU_SUCCESS_COLOR,
_defaults.LOGURU_SUCCESS_ICON,
),
"WARNING": Level(
_defaults.LOGURU_WARNING_NO,
_defaults.LOGURU_WARNING_COLOR,
_defaults.LOGURU_WARNING_ICON,
),
"ERROR": Level(
_defaults.LOGURU_ERROR_NO, _defaults.LOGURU_ERROR_COLOR, _defaults.LOGURU_ERROR_ICON
),
"CRITICAL": Level(
_defaults.LOGURU_CRITICAL_NO,
_defaults.LOGURU_CRITICAL_COLOR,
_defaults.LOGURU_CRITICAL_ICON,
),
}
_handlers_count = itertools.count()
_handlers = {}
_extra_class = {}
_min_level = float("inf")
_enabled = {}
_activation_list = []
_lock = threading.Lock()
def __init__(self, extra, exception, record, lazy, ansi, raw, depth):
self._extra = extra
self._record = record
self._exception = exception
self._lazy = lazy
self._ansi = ansi
self._raw = raw
self._depth = depth
def add(
self,
sink,
*,
level=_defaults.LOGURU_LEVEL,
format=_defaults.LOGURU_FORMAT,
filter=_defaults.LOGURU_FILTER,
colorize=_defaults.LOGURU_COLORIZE,
serialize=_defaults.LOGURU_SERIALIZE,
backtrace=_defaults.LOGURU_BACKTRACE,
diagnose=_defaults.LOGURU_DIAGNOSE,
enqueue=_defaults.LOGURU_ENQUEUE,
catch=_defaults.LOGURU_CATCH,
**kwargs
):
r"""Add a handler sending log messages to a sink adequately configured.
Parameters
----------
sink : |file-like object|_, |str|, |Path|, |function|_, |Handler| or |class|_
An object in charge of receiving formatted logging messages and propagating them to an
appropriate endpoint.
level : |int| or |str|, optional
The minimum severity level from which logged messages should be sent to the sink.
format : |str| or |function|_, optional
The template used to format logged messages before being sent to the sink.
filter : |function|_ or |str|, optional
A directive used to optionally filter out logged messages before they are sent to the
sink.
colorize : |bool|, optional
Whether or not the color markups contained in the formatted message should be converted
to ansi codes for terminal coloration, or stripped otherwise. If ``None``, the choice
is automatically made based on the sink being a tty or not.
serialize : |bool|, optional
Whether or not the logged message and its records should be first converted to a JSON
string before being sent to the sink.
backtrace : |bool|, optional
Whether or not the exception trace formatted should be extended upward, beyond the
catching point, to show the full stacktrace which generated the error.
diagnose : |bool|, optional
Whether or not the exception trace should display the variables values to eases the
debugging. This should be set to ``False`` in production to avoid leaking sensitive
data.
enqueue : |bool|, optional
Whether or not the messages to be logged should first pass through a multiprocess-safe
queue before reaching the sink. This is useful while logging to a file through multiple
processes.
catch : |bool|, optional
Whether or not errors occurring while sink handles logs messages should be caught or
not. If ``True``, an exception message is displayed on |sys.stderr| but the exception is
not propagated to the caller, preventing your app to crash.
**kwargs
Additional parameters that will be passed to the sink while creating it or while
logging messages (the exact behavior depends on the sink type).
If and only if the sink is a file, the following parameters apply:
Parameters
----------
rotation : |str|, |int|, |time|, |timedelta| or |function|_, optional
A condition indicating whenever the current logged file should be closed and a new one
started.
retention : |str|, |int|, |timedelta| or |function|_, optional
A directive filtering old files that should be removed during rotation or end of
program.
compression : |str| or |function|_, optional
A compression or archive format to which log files should be converted at closure.
delay : |bool|, optional
Whether or not the file should be created as soon as the sink is configured, or delayed
until first logged message. It defaults to ``False``.
mode : |str|, optional
The opening mode as for built-in |open| function. It defaults to ``"a"`` (open the
file in appending mode).
buffering : |int|, optional
The buffering policy as for built-in |open| function. It defaults to ``1`` (line
buffered file).
encoding : |str|, optional
The file encoding as for built-in |open| function. If ``None``, it defaults to
``locale.getpreferredencoding()``.
**kwargs
Others parameters are passed to the built-in |open| function.
Returns
-------
:class:`int`
An identifier associated with the added sink and which should be used to
|remove| it.
Notes
-----
Extended summary follows.
.. _sink:
.. rubric:: The sink parameter
The ``sink`` handles incoming log messages and proceed to their writing somewhere and
somehow. A sink can take many forms:
- A |file-like object|_ like ``sys.stderr`` or ``open("somefile.log", "w")``. Anything with
a ``.write()`` method is considered as a file-like object. If it has a ``.flush()``
method, it will be automatically called after each logged message. If it has a ``.stop()``
method, it will be automatically called at sink termination.
- A file path as |str| or |Path|. It can be parametrized with some additional parameters,
see below.
- A simple |function|_ like ``lambda msg: print(msg)``. This allows for logging
procedure entirely defined by user preferences and needs.
- A built-in |Handler| like ``logging.StreamHandler``. In such a case, the `Loguru` records
are automatically converted to the structure expected by the |logging| module.
- A |class|_ object that will be used to instantiate the sink using ``**kwargs`` attributes
passed. Hence the class should instantiate objects which are therefore valid sinks.
Note that you should avoid using the ``logger`` inside any of your sinks as this would
result in infinite recursion or dead lock if the module's sink was not explicitly disabled.
.. _message:
.. rubric:: The logged message
The logged message passed to all added sinks is nothing more than a string of the
formatted log, to which a special attribute is associated: the ``.record`` which is a dict
containing all contextual information possibly needed (see below).
Logged messages are formatted according to the ``format`` of the added sink. This format
is usually a string containing braces fields to display attributes from the record dict.
If fine-grained control is needed, the ``format`` can also be a function which takes the
record as parameter and return the format template string. However, note that in such a
case, you should take care of appending the line ending and exception field to the returned
format, while ``"\n{exception}"`` is automatically appended for convenience if ``format`` is
a string.
The ``filter`` attribute can be used to control which messages are effectively passed to the
sink and which one are ignored. A function can be used, accepting the record as an
argument, and returning ``True`` if the message should be logged, ``False`` otherwise. If
a string is used, only the records with the same ``name`` and its children will be allowed.
.. _levels:
.. rubric:: The severity levels
Each logged message is associated with a severity level. These levels make it possible to
prioritize messages and to choose the verbosity of the logs according to usages. For
example, it allows to display some debugging information to a developer, while hiding it to
the end user running the application.
The ``level`` attribute of every added sink controls the minimum threshold from which log
messages are allowed to be emitted. While using the ``logger``, you are in charge of
configuring the appropriate granularity of your logs. It is possible to add even more custom
levels by using the |level| method.
Here are the standard levels with their default severity value, each one is associated with
a logging method of the same name:
+----------------------+------------------------+------------------------+
| Level name | Severity value | Logger method |
+======================+========================+========================+
| ``TRACE`` | 5 | |logger.trace| |
+----------------------+------------------------+------------------------+
| ``DEBUG`` | 10 | |logger.debug| |
+----------------------+------------------------+------------------------+
| ``INFO`` | 20 | |logger.info| |
+----------------------+------------------------+------------------------+
| ``SUCCESS`` | 25 | |logger.success| |
+----------------------+------------------------+------------------------+
| ``WARNING`` | 30 | |logger.warning| |
+----------------------+------------------------+------------------------+
| ``ERROR`` | 40 | |logger.error| |
+----------------------+------------------------+------------------------+
| ``CRITICAL`` | 50 | |logger.critical| |
+----------------------+------------------------+------------------------+
.. _record:
.. rubric:: The record dict
The record is just a Python dict, accessible from sinks by ``message.record``. It contains
all contextual information of the logging call (time, function, file, line, level, etc.).
Each of its key can be used in the handler's ``format`` so the corresponding value is
properly displayed in the logged message (eg. ``"{level}"`` -> ``"INFO"``). Some record's
values are objects with two or more attributes, those can be formatted with ``"{key.attr}"``
(``"{key}"`` would display one by default). Formatting directives like ``"{key: >3}"`` also
works and is particularly useful for time (see below).
+------------+---------------------------------+----------------------------+
| Key | Description | Attributes |
+============+=================================+============================+
| elapsed | The time elapsed since the | See |timedelta| |
| | start of the program | |
+------------+---------------------------------+----------------------------+
| exception | The formatted exception if any, | ``type``, ``value``, |
| | ``None`` otherwise | ``traceback`` |
+------------+---------------------------------+----------------------------+
| extra | The dict of attributes | None |
| | bound by the user (see |bind|) | |
+------------+---------------------------------+----------------------------+
| file | The file where the logging call | ``name`` (default), |
| | was made | ``path`` |
+------------+---------------------------------+----------------------------+
| function | The function from which the | None |
| | logging call was made | |
+------------+---------------------------------+----------------------------+
| level | The severity used to log the | ``name`` (default), |
| | the message | ``no``, ``icon`` |
+------------+---------------------------------+----------------------------+
| line | The line number in the source | None |
| | code | |
+------------+---------------------------------+----------------------------+
| message | The logged message (not yet | None |
| | formatted) | |
+------------+---------------------------------+----------------------------+
| module | The module where the logging | None |
| | call was made | |
+------------+---------------------------------+----------------------------+
| name | The ``__name__`` where the | None |
| | logging call was made | |
+------------+---------------------------------+----------------------------+
| process | The process in which the | ``name``, ``id`` (default) |
| | logging call was made | |
+------------+---------------------------------+----------------------------+
| thread | The thread in which the | ``name``, ``id`` (default) |
| | logging call was made | |
+------------+---------------------------------+----------------------------+
| time | The aware local time when the | See |datetime| |
| | logging call was made | |
+------------+---------------------------------+----------------------------+
.. _time:
.. rubric:: The time formatting
To use your favorite time representation, you can set it directly in the time formatter
specifier of your handler format, like for example ``format="{time:HH:mm:ss} {message}"``.
Note that this datetime represents your local time, and it is also made timezone-aware,
so you can display the UTC offset to avoid ambiguities.
The time field can be formatted using more human-friendly tokens. Those constitute a subset
of the one used by the `Pendulum`_ library of `@sdispater`_. To escape a token, just add
square brackets around it, for example ``"[YY]"`` would display literally ``"YY"``.
If no time formatter specifier is used, like for example if ``format="{time} {message}"``,
the default one will use ISO 8601.
+------------------------+---------+----------------------------------------+
| | Token | Output |
+========================+=========+========================================+
| Year | YYYY | 2000, 2001, 2002 ... 2012, 2013 |
| +---------+----------------------------------------+
| | YY | 00, 01, 02 ... 12, 13 |
+------------------------+---------+----------------------------------------+
| Quarter | Q | 1 2 3 4 |
+------------------------+---------+----------------------------------------+
| Month | MMMM | January, February, March ... |
| +---------+----------------------------------------+
| | MMM | Jan, Feb, Mar ... |
| +---------+----------------------------------------+
| | MM | 01, 02, 03 ... 11, 12 |
| +---------+----------------------------------------+
| | M | 1, 2, 3 ... 11, 12 |
+------------------------+---------+----------------------------------------+
| Day of Year | DDDD | 001, 002, 003 ... 364, 365 |
| +---------+----------------------------------------+
| | DDD | 1, 2, 3 ... 364, 365 |
+------------------------+---------+----------------------------------------+
| Day of Month | DD | 01, 02, 03 ... 30, 31 |
| +---------+----------------------------------------+
| | D | 1, 2, 3 ... 30, 31 |
+------------------------+---------+----------------------------------------+
| Day of Week | dddd | Monday, Tuesday, Wednesday ... |
| +---------+----------------------------------------+
| | ddd | Mon, Tue, Wed ... |
| +---------+----------------------------------------+
| | d | 0, 1, 2 ... 6 |
+------------------------+---------+----------------------------------------+
| Days of ISO Week | E | 1, 2, 3 ... 7 |
+------------------------+---------+----------------------------------------+
| Hour | HH | 00, 01, 02 ... 23, 24 |
| +---------+----------------------------------------+
| | H | 0, 1, 2 ... 23, 24 |
| +---------+----------------------------------------+
| | hh | 01, 02, 03 ... 11, 12 |
| +---------+----------------------------------------+
| | h | 1, 2, 3 ... 11, 12 |
+------------------------+---------+----------------------------------------+
| Minute | mm | 00, 01, 02 ... 58, 59 |
| +---------+----------------------------------------+
| | m | 0, 1, 2 ... 58, 59 |
+------------------------+---------+----------------------------------------+
| Second | ss | 00, 01, 02 ... 58, 59 |
| +---------+----------------------------------------+
| | s | 0, 1, 2 ... 58, 59 |
+------------------------+---------+----------------------------------------+
| Fractional Second | S | 0 1 ... 8 9 |
| +---------+----------------------------------------+
| | SS | 00, 01, 02 ... 98, 99 |
| +---------+----------------------------------------+
| | SSS | 000 001 ... 998 999 |
| +---------+----------------------------------------+
| | SSSS... | 000[0..] 001[0..] ... 998[0..] 999[0..]|
| +---------+----------------------------------------+
| | SSSSSS | 000000 000001 ... 999998 999999 |
+------------------------+---------+----------------------------------------+
| AM / PM | A | AM, PM |
+------------------------+---------+----------------------------------------+
| Timezone | Z | -07:00, -06:00 ... +06:00, +07:00 |
| +---------+----------------------------------------+
| | ZZ | -0700, -0600 ... +0600, +0700 |
| +---------+----------------------------------------+
| | zz | EST CST ... MST PST |
+------------------------+---------+----------------------------------------+
| Seconds timestamp | X | 1381685817, 1234567890.123 |
+------------------------+---------+----------------------------------------+
| Microseconds timestamp | x | 1234567890123 |
+------------------------+---------+----------------------------------------+
.. _file:
.. rubric:: The file sinks
If the sink is a |str| or a |Path|, the corresponding file will be opened for writing logs.
The path can also contain a special ``"{time}"`` field that will be formatted with the
current date at file creation.
The ``rotation`` check is made before logging each message. If there is already an existing
file with the same name that the file to be created, then the existing file is renamed by
appending the date to its basename to prevent file overwriting. This parameter accepts:
- an |int| which corresponds to the maximum file size in bytes before that the current
logged file is closed and a new one started over.
- a |timedelta| which indicates the frequency of each new rotation.
- a |time| which specifies the hour when the daily rotation should occur.
- a |str| for human-friendly parametrization of one of the previously enumerated types.
Examples: ``"100 MB"``, ``"0.5 GB"``, ``"1 month 2 weeks"``, ``"4 days"``, ``"10h"``,
``"monthly"``, ``"18:00"``, ``"sunday"``, ``"w0"``, ``"monday at 12:00"``, ...
- a |function|_ which will be called before logging. It should accept two
arguments: the logged message and the file object, and it should return ``True`` if
the rotation should happen now, ``False`` otherwise.
The ``retention`` occurs at rotation or at sink stop if rotation is ``None``. Files are
selected according to their basename, if it is the same that the sink file, with possible
time field being replaced with ``.*``. This parameter accepts:
- an |int| which indicates the number of log files to keep, while older files are removed.
- a |timedelta| which specifies the maximum age of files to keep.
- a |str| for human-friendly parametrization of the maximum age of files to keep.
Examples: ``"1 week, 3 days"``, ``"2 months"``, ...
- a |function|_ which will be called before the retention process. It should accept the list
of log files as argument and process to whatever it wants (moving files, removing them,
etc.).
The ``compression`` happens at rotation or at sink stop if rotation is ``None``. This
parameter accepts:
- a |str| which corresponds to the compressed or archived file extension. This can be one
of: ``"gz"``, ``"bz2"``, ``"xz"``, ``"lzma"``, ``"tar"``, ``"tar.gz"``, ``"tar.bz2"``,
``"tar.xz"``, ``"zip"``.
- a |function|_ which will be called before file termination. It should accept the path
of the log file as argument and process to whatever it wants (custom compression,
network sending, removing it, etc.).
.. _color:
.. rubric:: The color markups
To add colors to your logs, you just have to enclose your format string with the appropriate
tags. This is based on the great `ansimarkup`_ library from `@gvalkov`_. Those tags are
removed if the sink don't support ansi codes.
The special tag ``<level>`` (abbreviated with ``<lvl>``) is transformed according to
the configured color of the logged message level.
Here are the available tags (note that compatibility may vary depending on terminal):
+------------------------------------+--------------------------------------+
| Color (abbr) | Styles (abbr) |
+====================================+======================================+
| Black (k) | Bold (b) |
+------------------------------------+--------------------------------------+
| Blue (e) | Dim (d) |
+------------------------------------+--------------------------------------+
| Cyan (c) | Normal (n) |
+------------------------------------+--------------------------------------+
| Green (g) | Italic (i) |
+------------------------------------+--------------------------------------+
| Magenta (m) | Underline (u) |
+------------------------------------+--------------------------------------+
| Red (r) | Strike (s) |
+------------------------------------+--------------------------------------+
| White (w) | Reverse (r) |
+------------------------------------+--------------------------------------+
| Yellow (y) | Blink (l) |
+------------------------------------+--------------------------------------+
| | Hide (h) |
+------------------------------------+--------------------------------------+
Usage:
+-----------------+-------------------------------------------------------------------+
| Description | Examples |
| +---------------------------------+---------------------------------+
| | Foreground | Background |
+=================+=================================+=================================+
| Basic colors | ``<red>``, ``<r>`` | ``<GREEN>``, ``<G>`` |
+-----------------+---------------------------------+---------------------------------+
| Light colors | ``<light-blue>``, ``<le>`` | ``<LIGHT-CYAN>``, ``<LC>`` |
+-----------------+---------------------------------+---------------------------------+
| Xterm colors | ``<fg 86>``, ``<fg 255>`` | ``<bg 42>``, ``<bg 9>`` |
+-----------------+---------------------------------+---------------------------------+
| Hex colors | ``<fg #00005f>``, ``<fg #EE1>`` | ``<bg #AF5FD7>``, ``<bg #fff>`` |
+-----------------+---------------------------------+---------------------------------+
| RGB colors | ``<fg 0,95,0>`` | ``<bg 72,119,65>`` |
+-----------------+---------------------------------+---------------------------------+
| Stylizing | ``<bold>``, ``<b>`` , ``<underline>``, ``<u>`` |
+-----------------+-------------------------------------------------------------------+
| Shorthand | ``<red, yellow>``, ``<r, y>`` |
| (FG, BG) | |
+-----------------+-------------------------------------------------------------------+
| Shorthand | ``<bold, cyan, white>``, ``<b,,w>``, ``<b,c,>`` |
| (Style, FG, BG) | |
+-----------------+-------------------------------------------------------------------+
.. _env:
.. rubric:: The environment variables
The default values of sink parameters can be entirely customized. This is particularly
useful if you don't like the log format of the pre-configured sink.
Each of the |add| default parameter can be modified by setting the ``LOGURU_[PARAM]``
environment variable. For example on Linux: ``export LOGURU_FORMAT="{time} - {message}"``
or ``export LOGURU_DIAGNOSE=NO``.
The default levels' attributes can also be modified by setting the ``LOGURU_[LEVEL]_[ATTR]``
environment variable. For example, on Windows: ``setx LOGURU_DEBUG_COLOR "<blue>"``
or ``setx LOGURU_TRACE_ICON "🚀"``.
If you want to disable the pre-configured sink, you can set the ``LOGURU_AUTOINIT``
variable to ``False``.
On Linux, you will probably need to edit the ``~/.profile`` file to make this persistent. On
Windows, don't forget to restart your terminal for the change to be taken into account.
Examples
--------
>>> logger.add(sys.stdout, format="{time} - {level} - {message}", filter="sub.module")
>>> logger.add("file_{time}.log", level="TRACE", rotation="100 MB")
>>> def my_sink(message):
... record = message.record
... update_db(message, time=record.time, level=record.level)
...
>>> logger.add(my_sink)
>>> from logging import StreamHandler
>>> logger.add(StreamHandler(sys.stderr), format="{message}")
>>> class RandomStream:
... def __init__(self, seed, threshold):
... self.threshold = threshold
... random.seed(seed)
... def write(self, message):
... if random.random() > self.threshold:
... print(message)
...
>>> stream_object = RandomStream(seed=12345, threhold=0.25)
>>> logger.add(stream_object, level="INFO")
>>> logger.add(RandomStream, level="DEBUG", seed=34567, threshold=0.5)
"""
if colorize is None and serialize:
colorize = False
if isclass(sink):
sink = sink(**kwargs)
return self.add(
sink,
level=level,
format=format,
filter=filter,
colorize=colorize,
serialize=serialize,
backtrace=backtrace,
diagnose=diagnose,
enqueue=enqueue,
catch=catch,
)
elif isinstance(sink, (str, PathLike)):
path = sink
sink = FileSink(path, **kwargs)
return self.add(
sink,
level=level,
format=format,
filter=filter,
colorize=colorize,
serialize=serialize,
backtrace=backtrace,
diagnose=diagnose,
enqueue=enqueue,
catch=catch,
)
elif hasattr(sink, "write") and callable(sink.write):
if colorize is False:
stream = sink
else:
try:
converter = AnsiToWin32(sink, convert=None, strip=False)
isatty = converter.stream.isatty()
except Exception:
if colorize is None:
colorize = False
stream = sink
else:
if colorize is None:
colorize = isatty
if converter.should_wrap() and colorize:
stream = converter.stream
else:
stream = sink
stream_write = stream.write
if kwargs:
def write(m):
return stream_write(m, **kwargs)
else:
write = stream_write
if hasattr(stream, "flush") and callable(stream.flush):
stream_flush = stream.flush
def writer(m):
write(m)
stream_flush()
else:
writer = write
if hasattr(stream, "stop") and callable(stream.stop):
stopper = stream.stop
else:
def stopper():
return None
elif isinstance(sink, logging.Handler):
def writer(m):
message = str(m)
r = m.record
exc = r["exception"]
if not is_formatter_dynamic:
message = message[:-1]
record = logging.root.makeRecord(
r["name"],
r["level"].no,
r["file"].path,
r["line"],
message,
(),
(exc.type, exc.value, exc.traceback) if exc else None,
r["function"],
r["extra"],
**kwargs
)
if exc:
record.exc_text = "\n"
sink.handle(record)
stopper = sink.close
if colorize is None:
colorize = False
elif callable(sink):
if kwargs:
def writer(m):
return sink(m, **kwargs)
else:
writer = sink
def stopper():
return None
if colorize is None:
colorize = False
else:
raise ValueError("Cannot log to objects of type '%s'." % type(sink).__name__)
if filter is None or filter == "":
filter_func = None
elif isinstance(filter, str):
parent = filter + "."
length = len(parent)
def filter_func(r):
return (r["name"] + ".")[:length] == parent
elif callable(filter):
filter_func = filter
else:
raise ValueError(
"Invalid filter, it should be a function or a string, not: '%s'"
% type(filter).__name__
)
if isinstance(level, str):
levelno = self.level(level).no
elif isinstance(level, int):
levelno = level
else:
raise ValueError(
"Invalid level, it should be an integer or a string, not: '%s'"
% type(level).__name__
)
if levelno < 0:
raise ValueError(
"Invalid level value, it should be a positive integer, not: %d" % levelno
)
if isinstance(format, str):
formatter = format + "\n{exception}"
is_formatter_dynamic = False
elif callable(format):
formatter = format
is_formatter_dynamic = True
else:
raise ValueError(
"Invalid format, it should be a string or a function, not: '%s'"
% type(format).__name__
)
try:
encoding = sink.encoding
except AttributeError:
encoding = None
if not encoding:
encoding = "ascii"
with self._lock:
handler_id = next(self._handlers_count)
colors = [lvl.color for lvl in self._levels.values()] + [""]
exception_formatter = ExceptionFormatter(
colorize=colorize,
encoding=encoding,
diagnose=diagnose,
backtrace=backtrace,
hidden_frames_filename=self.catch.__code__.co_filename,
)
handler = Handler(
writer=writer,
stopper=stopper,
levelno=levelno,
formatter=formatter,
is_formatter_dynamic=is_formatter_dynamic,
filter_=filter_func,
colorize=colorize,
serialize=serialize,
catch=catch,
enqueue=enqueue,
id_=handler_id,
exception_formatter=exception_formatter,
colors=colors,
)
handlers = self._handlers.copy()
handlers[handler_id] = handler
self.__class__._min_level = min(self.__class__._min_level, levelno)
self.__class__._handlers = handlers
return handler_id
def remove(self, handler_id=None):
"""Remove a previously added handler and stop sending logs to its sink.
Parameters
----------
handler_id : |int| or ``None``
The id of the sink to remove, as it was returned by the |add| method. If ``None``, all
handlers are removed. The pre-configured handler is guaranteed to have the index ``0``.
Raises
------
ValueError
If ``handler_id`` is not ``None`` but there is no active handler with such id.
Examples
--------
>>> i = logger.add(sys.stderr, format="{message}")
>>> logger.info("Logging")
Logging
>>> logger.remove(i)
>>> logger.info("No longer logging")
"""
with self._lock:
handlers = self._handlers.copy()
if handler_id is None:
for handler in handlers.values():
handler.stop()
handlers.clear()
else:
try:
handler = handlers.pop(handler_id)
except KeyError:
raise ValueError("There is no existing handler with id '%s'" % handler_id)
handler.stop()
levelnos = (h.levelno for h in handlers.values())
self.__class__._min_level = min(levelnos, default=float("inf"))
self.__class__._handlers = handlers
def catch(
self,
exception=Exception,
*,
level="ERROR",
reraise=False,
message="An error has been caught in function '{record[function]}', "
"process '{record[process].name}' ({record[process].id}), "
"thread '{record[thread].name}' ({record[thread].id}):"
):
"""Return a decorator to automatically log possibly caught error in wrapped function.
This is useful to ensure unexpected exceptions are logged, the entire program can be
wrapped by this method. This is also very useful to decorate |Thread.run| methods while
using threads to propagate errors to the main logger thread.
Note that the visibility of variables values (which uses the cool `better_exceptions`_
library from `@Qix-`_) depends on the ``diagnose`` option of each configured sink.
The returned object can also be used as a context manager.
Parameters
----------
exception : |Exception|, optional
The type of exception to intercept. If several types should be caught, a tuple of
exceptions can be used too.
level : |str| or |int|, optional
The level name or severity with which the message should be logged.
reraise : |bool|, optional
Whether or not the exception should be raised again and hence propagated to the caller.
message : |str|, optional
The message that will be automatically logged if an exception occurs. Note that it will
be formatted with the ``record`` attribute.
Returns
-------
decorator / context manager
An object that can be used to decorate a function or as a context manager to log
exceptions possibly caught.
Examples
--------
>>> @logger.catch
... def f(x):
... 100 / x
...
>>> def g():
... f(10)
... f(0)
...
>>> g()
ERROR - An error has been caught in function 'g', process 'Main' (367), thread 'ch1' (1398):
Traceback (most recent call last):
File "program.py", line 12, in <module>
g()
└ <function g at 0x7f225fe2bc80>
> File "program.py", line 10, in g
f(0)
└ <function f at 0x7f225fe2b9d8>
File "program.py", line 6, in f
100 / x
└ 0
ZeroDivisionError: division by zero
>>> with logger.catch(message="Because we never know..."):
... main() # No exception, no logs
...
"""
if callable(exception) and (
not isclass(exception) or not issubclass(exception, BaseException)
):
return self.catch()(exception)
class Catcher:
def __init__(self, as_decorator):
self._as_decorator = as_decorator
def __enter__(self_):
return None
def __exit__(self_, type_, value, traceback_):
if type_ is None:
return
if not issubclass(type_, exception):
return False
if self_._as_decorator:
back = 2
else:
back = 1
logger_ = self.opt(
exception=True,
record=True,
lazy=self._lazy,
ansi=self._ansi,
raw=self._raw,
depth=self._depth + back,
)
log = logger_._make_log_function(level)
log(logger_, message)
return not reraise
def __call__(_, function):
catcher = Catcher(True)
if inspect.iscoroutinefunction(function):
async def catch_wrapper(*args, **kwargs):
with catcher:
return await function(*args, **kwargs)
elif inspect.isgeneratorfunction(function):
def catch_wrapper(*args, **kwargs):