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pip install loguru

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from loguru import logger
logger.debug("这是一个调试信息")

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from loguru import logger
logger.debug("这是一条跟踪消息")
logger.debug("这是一条调试信息")
logger.info("这是一条普通信息")
logger.success("操作成功完成")
logger.warning("这是一条警告信息")
logger.error("这是一条错误信息")
logger.critical("这是一条严重错误信息")

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#coding:utf-8
 from atexit import register
from random import randrange
from threading import Thread, Lock, current_thread
from time import sleep, ctime
 from loguru import logger
 class CleanOutputSet(set):
    def __str__(self):
        return ','.join(x for x in self)
 lock = Lock()
loops = (randrange(2, 5) for x in range(randrange(3, 7)))
remaining = CleanOutputSet()
 def loop(nsec):
    myname = current_thread().name
     logger.info("Startted {}", myname)
     '''
    锁的申请和释放交给with上下文管理器
    '''
    with lock:
        remaining.add(myname)
    sleep(nsec)
     logger.info("Completed {} ({} secs)", myname, nsec)
     with lock:
        remaining.remove(myname)
        logger.info("Remaining:{}", (remaining or 'NONE'))
 '''
_main()函数是一个特殊的函数，只有这个模块从命令行直接运行时才会执行该函数（不能被其他模块导入）
'''
def _main():
    for pause in loops:
        Thread(target=loop, args=(pause,)).start()
 '''
这个函数（装饰器的方式）会在python解释器中注册一个退出函数，也就是说，他会在脚本退出之前请求调用这个特殊函数
'''
@register
def _atexit():
    logger.info("All Thread DONE!")
    logger.info("\n===========================================================================\n")
 if __name__=='__main__':
    logger.add("run.log")
     _main()

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from loguru import logger
import sys
# 终端显示不受该段代码设置
# 添加一个日志处理器，输出到文件
# 设置日志最低显示级别为INFO，format将设置sink中的内容
# sink链接的本地文件，如不存在则新建。如果存在则追写
logger.add(sink="myapp.log", level="INFO", format="{time:HH:mm:ss}  | {message}| {level}")
# debug结果不被显示到本地文件
logger.debug("这是一条调试信息")
logger.info("这是一条普通信息")

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from loguru import logger
logger.add(sink="myapp1.log", level="INFO")
logger.add(sink="myapp2.log", level="INFO")
# 会同时存入所有add添加日志处理器
logger.info("这是一条普通信息，存入myapp2")

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from loguru import logger
import sys
# 移除所有日志处理器（包括终端输出）
logger.remove()
logger.add(sink="myapp3.log", level="INFO", format="{time:HH:mm:ss}  | {message}| {level}")
logger.debug("这是一条调试信息存入myapp3")
logger.info("这是一条普通信息存入myapp3")

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from loguru import logger
# 移除所有日志处理器（包括终端输出）
logger.remove()
# 没有输出
logger.info("这是一条普通信息存入myapp3")

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from loguru import logger
# 移除默认终端logger，如果终端存在。
# logger.remove(0)
# 添加多个文件处理器，enqueu设置异步日志记录
handler1 = logger.add("myapp1.log", enqueue=True)
print(handler1) # handler_id是移除的处理器的唯一标识符
handler2 = logger.add("myapp2.log")
# 记录一些日志
logger.info("这些信息会被记录到两个文件中")
# 移除特定的文件处理器
logger.remove(handler1)
# 现在只有myapp2.log 会记录日志
logger.info("这条信息只会记录在myapp2.log 中")

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from loguru import logger
import sys
logger.remove() # 移除默认输出
# 添加一个日志处理器，输出到控制台，使用自定义格式
logger.add(
    sink=sys.stdout,
    level="DEBUG",
    # green表示颜色
    format="<green>{time:HH:mm}</green> <level>{message}</level>"
)
# 注意终端显示会同步显示
logger.debug("这是一条调试信息")
logger.info("这是一条普通信息")

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from datetime import datetime
from loguru import logger
# 自定义时间格式
# time_format = "%Y-%m-%d %H:%M:%S,%f"  # 包括微秒
time_format = "%H:%M:%S,%f"  # 包括微秒但不含年月日
# 定义日志格式，使用 datetime.now().strftime() 来格式化时间
log_format = "{time:" + time_format + "} - {level} - {message}"
logger.add("myapp.log", format=log_format, level="DEBUG")
# 记录一条日志
logger.debug("这是一个带有微秒的测试日志")

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logger.add("file_1.log", rotation="500 MB")    # Automatically rotate too big file

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logger.add("file_2.log", rotation="12:00")     # New file is created each day at noon

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logger.add("file_3.log", rotation="1 week")

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logger.add("file_X.log", retention="10 days")  # Cleanup after some time

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logger.add("file_Y.log", compression="zip")    # Save some loved space

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from loguru import logger
# 当文件大小达到100MB时创建新的日志文件，旧文件保留并重命名，用于防止单个日志文件变得过大。
logger.add("file_1.log", rotation="100 MB")
# 每天中午12时创建新的日志文件，旧文件保留并重命名
logger.add("file_2.log", rotation="12:00")
# 当日志文件存在超过一周时创建新的日志文件，旧文件保留并重命名
logger.add("file_3.log", rotation="1 week")
# 设置日志文件保留10天
logger.add("file_4.log", retention="10 days")
# 当文件大小达到100MB时创建新的日志文件，旧文件保留压缩为zip文件
logger.add('file_{time}.log', rotation="100 MB", compression='zip')

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from loguru import logger
logger.add(sink='myapp.log')
@logger.catch
def my_function(x, y):
    return x / y
        res = my_function(0,0)

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from loguru import logger
 logger.add("runtime.log") 
 def my_function1():
    try:
        return 1 / 0
    except Exception as e:
        logger.exception(f"What?! {e}")
 my_function1()

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2025-04-09 17:11:36.156 | ERROR    | __main__:my_function1:9 - What?! division by zero
Traceback (most recent call last):
  File "/home/vvd/anaconda3/envs/boeye/lib/python3.10/runpy.py", line 196, in _run_module_as_main
    return _run_code(code, main_globals, None,
           │         │     └ {'__name__': '__main__', '__doc__': None, '__package__': '', '__loader__': <_frozen_importlib_external.SourceFileLoader objec...
           │         └ <code object <module> at 0x7681d4e42130, file "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs...
           └ <function _run_code at 0x7681d4e46e60>
  File "/home/vvd/anaconda3/envs/boeye/lib/python3.10/runpy.py", line 86, in _run_code
    exec(code, run_globals)
         │     └ {'__name__': '__main__', '__doc__': None, '__package__': '', '__loader__': <_frozen_importlib_external.SourceFileLoader objec...
         └ <code object <module> at 0x7681d4e42130, file "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs...
  File "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/debugpy/adapter/../../debugpy/launcher/../../debugpy/__main__.py", line 71, in <module>
    cli.main()
    │   └ <function main at 0x7681d3b21510>
    └ <module 'debugpy.server.cli' from '/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/debugpy/ada...
  File "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/debugpy/adapter/../../debugpy/launcher/../../debugpy/../debugpy/server/cli.py", line 501, in main
    run()
    └ <function run_file at 0x7681d3b212d0>
  File "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/debugpy/adapter/../../debugpy/launcher/../../debugpy/../debugpy/server/cli.py", line 351, in run_file
    runpy.run_path(target, run_name="__main__")
    │     │        └ '/home/vvd/Works/lab/loguru/logtest.py'
    │     └ <function run_path at 0x7681d40840d0>
    └ <module '_pydevd_bundle.pydevd_runpy' from '/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/de...
  File "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_runpy.py", line 310, in run_path
    return _run_module_code(code, init_globals, run_name, pkg_name=pkg_name, script_name=fname)
           │                │     │             │                  │                     └ '/home/vvd/Works/lab/loguru/logtest.py'
           │                │     │             │                  └ ''
           │                │     │             └ '__main__'
           │                │     └ None
           │                └ <code object <module> at 0x7681d3c06d90, file "/home/vvd/Works/lab/loguru/logtest.py", line 1>
           └ <function _run_module_code at 0x7681d4053d00>
  File "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_runpy.py", line 127, in _run_module_code
    _run_code(code, mod_globals, init_globals, mod_name, mod_spec, pkg_name, script_name)
    │         │     │            │             │         │         │         └ '/home/vvd/Works/lab/loguru/logtest.py'
    │         │     │            │             │         │         └ ''
    │         │     │            │             │         └ None
    │         │     │            │             └ '__main__'
    │         │     │            └ None
    │         │     └ {'__name__': '__main__', '__doc__': None, '__package__': '', '__loader__': None, '__spec__': None, '__file__': '/home/vvd/Wor...
    │         └ <code object <module> at 0x7681d3c06d90, file "/home/vvd/Works/lab/loguru/logtest.py", line 1>
    └ <function _run_code at 0x7681d4053910>
  File "/home/vvd/.vscode/extensions/ms-python.debugpy-2025.6.0-linux-x64/bundled/libs/debugpy/_vendored/pydevd/_pydevd_bundle/pydevd_runpy.py", line 118, in _run_code
    exec(code, run_globals)
         │     └ {'__name__': '__main__', '__doc__': None, '__package__': '', '__loader__': None, '__spec__': None, '__file__': '/home/vvd/Wor...
         └ <code object <module> at 0x7681d3c06d90, file "/home/vvd/Works/lab/loguru/logtest.py", line 1>
  File "/home/vvd/Works/lab/loguru/logtest.py", line 11, in <module>
    my_function1()
    └ <function my_function1 at 0x7681d39725f0>
> File "/home/vvd/Works/lab/loguru/logtest.py", line 7, in my_function1
    return 1 / 0
ZeroDivisionError: division by zero

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from loguru import logger
# 添加自定义日志级别
logger.level("TRACE", no=5, color="<blue>", icon="🐞")
# 使用自定义日志级别
logger.trace("this is a trace log")

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from loguru import logger
# 定义一个过滤器函数
def my_filter(record):
    # 只记录包含 "第一" 的日志
    return "第一" in record["message"]
# 使用过滤器
logger.add("myapp.log", filter=my_filter)
# 记录一些日志
logger.info("第一个记录")
logger.info("第二个记录")

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from loguru import logger
def filter_user(record):
    return record["extra"].get("user") =="A"
logger.add("myapp.log", filter=filter_user)
# 绑定user
logger.bind(user="A").info("来自A")
logger.bind(user="B").info("来自B")

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from loguru import logger
# 设置不同级别的日志输出文件
logger.add("debug.log", level="DEBUG", rotation="10 MB", filter=lambda record: record["level"].name == "DEBUG")
logger.add("info.log", level="INFO", rotation="10 MB", filter=lambda record: record["level"].name == "INFO")
logger.add("warning.log", level="WARNING", rotation="10 MB", filter=lambda record: record["level"].name == "WARNING")
logger.add("error.log", level="ERROR", rotation="10 MB", filter=lambda record: record["level"].name == "ERROR")
logger.add("critical.log", level="CRITICAL", rotation="10 MB", filter=lambda record: record["level"].name == "CRITICAL")
# 输出不同级别的日志消息
logger.debug("This is a debug message")
logger.info("This is an info message")
logger.warning("This is a warning message")
logger.error("This is an error message")
logger.critical("This is a critical message")

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from loguru import logger
# 绑定一个user_id参数
logger = logger.bind(user_id=12345)
# 输出带有user_id参数的日志信息
logger.info("user {user_id} logged in")

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from loguru import logger
# 创建一个网络套接字
import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect(('localhost', 9000))
# 将日志记录器的输出发送到网络套接字中
logger.add(sock.sendall)
# 输出日志信息
logger.info("hello world")

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from loguru import logger
 logger.remove(handler_id=None)
 logger.add("runtime.log")       # 创建了一个文件名为runtime的log文件
 logger.debug("This's a log message in file")